Showing papers in "Journal of Bone and Joint Surgery-british Volume in 1996"
TL;DR: It is suggested that structural changes within the annulus and endplate lead to a transfer of load from the nucleus to the posterior annulus, and high 'stress' concentrations within the Annulus may cause pain, and lead to further disruption.
Abstract: We investigated the distribution of compressive 'stress' within cadaver intervertebral discs, using a pressure transducer mounted in a 13 mm diameter needle The needle was pulled along the midsagittal diameter of a lumbar disc with the face of the transducer either vertical or horizontal while the disc was subjected to a constant compressive force The resulting 'stress profiles' were analysed in order to characterise the distribution of vertical and horizontal compressive stress within each disc A total of 87 discs from subjects aged between 16 and 87 years was examined Our results showed that age-related degenerative changes reduced the diameter of the central hydrostatic region of each disc (the 'functional nucleus') by approximately 50%, and the pressure within this region fell by 30% The width of the functional annulus increased by 80% and the height of compressive 'stress peaks' within it by 160% The effects of age and degeneration were greater at L4/L5 than at L2/L3, and the posterior annulus was affected more than the anterior Age and degeneration were themselves closely related, but the stage of degeneration had the greater effect on stress distributions We suggest that structural changes within the annulus and endplate lead to a transfer of load from the nucleus to the posterior annulus High 'stress' concentrations within the annulus may cause pain, and lead to further disruption
667 citations
TL;DR: The shoulder questionnaire provides a measure of outcome for shoulder operations which is short, practical, reliable, valid and sensitive to clinically important changes.
Abstract: We developed a 12-item questionnaire for completion by patients having shoulder operations other than stabilisation. A prospective study of 111 patients was undertaken before operation and at follow-up six months later. Each patient completed the new questionnaire and the SF36 form. Some filled in the Stanford Health Assessment Questionnaire (HAQ). An orthopaedic surgeon assessed the Constant shoulder score. The single score derived from the questionnaire had a high internal consistency. Reproducibility, examined by test-retest reliability, was found to be satisfactory. The validity of the questionnaire was established by obtaining significant correlations in the expected direction with the Constant score and the relevant scales of the SF36 and the HAQ. Sensitivity to change was assessed by analysing the differences between the preoperative scores and those at follow-up. Changes in scores were compared with the patients' responses to postoperative questions about their condition. The standardised effect size for the new questionnaire compared favourably with that for the SF36 and the HAQ. The new questionnaire was the most efficient in distinguishing patients who said that their shoulder was much better from all other patients. The shoulder questionnaire provides a measure of outcome for shoulder operations which is short, practical, reliable, valid and sensitive to clinically important changes.
625 citations
TL;DR: In this series, the use of a differential pressure of 30 mmHg as a threshold for fasciotomy led to no missed cases of acute compartment syndrome and it was recommended that decompression should be performed if the differential pressure level drops to under 30mmHg.
Abstract: We made a prospective study of 116 patients with tibial diaphyseal fractures who had continuous monitoring of anterior compartment pressure for 24 hours. Three patients had acute compartment syndrome (2.6%). In the first 12 hours of monitoring, 53 patients had absolute pressures over 30 mmHg and 30 had pressures over 40 mmHg, with four higher than 50 mmHg. Only one patient had a differential pressure (diastolic minus compartment pressure) of less than 30 mmHg; he had a fasciotomy. In the second 12-hour period 28 patients had absolute pressures over 30 mmHg and seven over 40 mmHg. Only two had differential pressures of less than 30 mmHg; they had fasciotomies. None of our 116 patients had any sequelae of the compartment syndrome at their latest review at least six months after injury. A threshold for decompression of 30 mmHg would have indicated that 50 patients (43%) would have required fasciotomy, and at a 40 mmHg threshold 27 (23%) would have been considered for an unnecessary fasciotomy. In our series, the use of a differential pressure of 30 mmHg as a threshold for fasciotomy led to no missed cases of acute compartment syndrome. We recommended that decompression should be performed if the differential pressure level drops to under 30 mmHg.
464 citations
TL;DR: Young patients with distal femoral prostheses in whom a high percentage of the femur had been replaced had the poorest prognosis for survival without aseptic loosening, and neither the age nor the percentage of bone removed was a factor after proximal femoral replacement.
Abstract: We have made a retrospective study of 1001 custom-made prostheses used as replacements after surgery for bone tumours. There were 493 distal femoral, 263 proximal femoral and 245 proximal tibial prostheses. Aseptic loosening was shown to be the principal mode of failure of the implants, and 71 patients had revision for aseptic loosening of a cemented intramedullary stem. The probability of a patient surviving aseptic loosening for 120 months was 93.8% for a proximal femoral replacement, 67.4% for a distal femoral prosthesis and 58% for a proximal tibial implant. In patients with distal femoral replacements the age of the patient at the time of operation and the percentage of bone resected were related to the risk of aseptic loosening. Young patients with distal femoral prostheses in whom a high percentage of the femur had been replaced had the poorest prognosis for survival without aseptic loosening. The percentage of bone removed had a significant effect in the proximal tibial replacement group, but the age of the patient did not. By contrast, neither the age nor the percentage of bone removed was a factor after proximal femoral replacement. The significance of these findings is discussed in relation to mechanical factors.
398 citations
TL;DR: None of 116 patients with tibial diaphyseal fractures who had continuous monitoring of anterior compartment pressure for 24 hours had any sequelae of the compartment syndrome at their latest review at least six months after injury.
Abstract: We made a prospective study of 116 patients with tibial diaphyseal fractures who had continuous monitoring of anterior compartment pressure for 24 hours. Three patients had acute compartment syndrome (2.6%).In the first 12 hours of monitoring, 53 patients had absolute pressures over 30 mmHg and 30 had pressures over 40 mmHg, with four higher than 50 mmHg. Only one patient had a differential pressure (diastolic minus compartment pressure) of less than 30 mmHg; he had a fasciotomy.In the second 12-hour period 28 patients had absolute pressures over 30 mmHg and seven over 40 mmHg. Only two had differential pressures of less than 30 mmHg; they had fasciotomies. None of our 116 patients had any sequelae of the compartment syndrome at their latest review at least six months after injury.A threshold for decompression of 30 mmHg would have indicated that 50 patients (43%) would have required fasciotomy, and at a 40 mmHg threshold 27 (23%) would have been considered for an unnecessary fasciotomy.In our series, the...
346 citations
TL;DR: In this article, the effect of tranexamic acid on blood loss and blood transfusion in knee arthroplasty by a randomised, double-blind study of 86 patients was investigated.
Abstract: We investigated the effect of a fibrinolytic inhibitor, tranexamic acid, on blood loss and blood transfusion in knee arthroplasty by a randomised, double-blind study of 86 patients. A dose of 10 mg/kg body-weight of either tranexamic acid or placebo was given intravenously shortly before the release of the tourniquet, and repeated three hours later. The mean total blood loss was 730 +/- 280 ml in the tranexamic acid group as against 1410 +/- 480 ml in the placebo group (p < 0.001). Both the number of patients receiving blood transfusion and the number of blood units transfused were reduced to one-third in the treated group, and mean postoperative Hb concentrations were significantly higher after prophylaxis. The number of thromboembolic complications was the same in both groups. Tranexamic acid should be given prophylactically in order to be effective.
331 citations
TL;DR: The Constant-Murley (1987) assessment is found easy to use, with low inter- and intraobserver errors, but sufficiently imprecise in repeated measurements to give concern in its use for clinical follow-up of patients.
Abstract: We have analysed the Constant-Murley (1987) assessment for 25 patients with shoulder pathology. We found the score easy to use, with low inter- and intraobserver errors, but sufficiently imprecise in repeated measurements to give concern in its use for clinical follow-up of patients. We have calculated 95% confidence limits for a single assessment to be within 16 to 20 points in most cases. In addition, we found that all our subjects with instability as their main problem scored within five points of the maximum; this suggests that the scoring method may need to be revised for use on these patients.
328 citations
TL;DR: In the medium term, there did not find any significant benefit from resurfacing the patella during TKA for osteoarthritis if it was not severely deformed, and stair-climbing ability was significantly better in the retention group.
Abstract: We studied 40 patients in whom the patella was not severely deformed and who were undergoing primary total knee arthroplasty (TKA) for osteoarthritis by one surgeon using one type of prosthesis. They were randomly allocated either to have the patella retained or resurfaced with a cemented, all-polyethylene component regardless of the state of the patellar articular cartilage. Apart from removal of osteophytes, no surgery was undertaken on the retained patellae. All 38 surviving patients were evaluated at three years using the HSS knee score and a new, specifically designed Patellar score (maximum score of 30). No TKA was revised, but two patients in the resurfacing group had a further unrelated procedure. The mean HSS and Patellar scores at follow-up were 89 and 28 in the patellar retention group and 83 and 26 in the patellar resurfacing group. Statistically significant lower scores for both were recorded in women and in heavier patients. Stair-climbing ability was significantly better in the retention group. Although there were no complications related to patellar resurfacing, in the medium term we did not find any significant benefit from resurfacing the patella during TKA for osteoarthritis if it was not severely deformed.
327 citations
319 citations
TL;DR: Internal fixation of the scaphoid using the Herbert bone screw, although technically demanding, has few complications and appears to offer significant advantages over other methods of treatment.
Abstract: We reviewed the records of 431 patients who had open reduction and internal fixation of the scaphoid performed by one surgeon (TJH) over a 13-year period. The Herbert bone screw provided adequate internal fixation without the use of plaster immobilisation, promoting a rapid functional recovery. On average, patients returned to work 4.7 weeks after surgery and wrist function was significantly improved, even when the fracture failed to unite. Healing rates for acute fractures were better than those reported for plaster immobilisation and were independent of fracture location. In the case of established nonunions, healing depended on the stage and location of the fracture, but the progress of arthritis was halted and carpal collapse significantly improved. Internal fixation of the scaphoid using the Herbert bone screw, although technically demanding, has few complications and appears to offer significant advantages over other methods of treatment.
299 citations
TL;DR: The main influence on final outcome was carpal malalignment which had a statistically significant negative effect on function.
Abstract: We performed a prospective, randomised trial on 120 patients with redisplaced fractures of the distal radius comparing four methods of treatment. The four treatment groups, each containing 30 patients, were remanipulation and plaster, open reduction and bone grafting, and closed external fixation with and without mobilisation of the wrist at three weeks. The radiological results showed improvement in angulation of the distal radius for the open reduction and bone grafting group. Functional results at six weeks, three and six months and at one year, however, showed no difference between any of the four groups. The main influence on final outcome was carpal malalignment which had a statistically significant negative effect on function.
TL;DR: There was significant alleviation of pain and improvement of function after treatment in group I in which there was a good or excellent outcome in 48% and an acceptable result in 42% at the final review, compared with 6% and 24%, respectively, in group II.
Abstract: We report a controlled, prospective study to investigate the effect of treatment by low-energy extracorporeal shock waves on pain in tennis elbow. We assigned at random 100 patients who had had symptoms for more than 12 months to two groups to receive low-energy shock-wave therapy. Group I received a total of 3000 impulses of 0.08 mJ/mm 2 and group II, the control group, 30 impulses. The patients were reviewed after 3, 6 and 24 weeks. There was significant alleviation of pain and improvement of function after treatment in group I in which there was a good or excellent outcome in 48% and an acceptable result in 42% at the final review, compared with 6% and 24%, respectively, in group II.
TL;DR: It is recommended that, when equipment is available, all patients with tibial fractures should have continuous compartment monitoring to minimise the incidence of acute compartment syndrome.
Abstract: We reviewed 25 patients with tibial diaphyseal fractures which had been complicated by an acute compartment syndrome. Thirteen had undergone continuous monitoring of the compartment pressure and the other 12 had not. The average delay from injury to fasciotomy in the monitored group was 16 hours and in the non-monitored group 32 hours (p < 0.05). Of the 12 surviving patients in the monitored group, none had any sequelae of acute compartment syndrome at final review at an average of 10.5 months. Of the 11 surviving patients in the non-monitored group, ten had definite sequelae with muscle weakness and contractures (p < 0.01). There was also a significant delay in tibial union in the non-monitored group (p < 0.05). We recommend that, when equipment is available, all patients with tibial fractures should have continuous compartment monitoring to minimise the incidence of acute compartment syndrome.
TL;DR: In this article, the authors investigated susceptibility to infection after a local bacterial challenge using standard 2.0 dynamic compression plates of either stainless steel or titanium in rabbit tibiae, after the wounds had been closed, various concentrations of a strain of Staphylococcus aureus were inoculated percutaneously.
Abstract: Resistance to infection may be influenced by foreign bodies such as devices for fracture fixation. It is known that stainless steel and commercially-pure titanium have different biocompatibilities. We have investigated susceptibility to infection after a local bacterial challenge using standard 2.0 dynamic compression plates of either stainless steel or titanium in rabbit tibiae. After the wounds had been closed, various concentrations of a strain of Staphylococcus aureus were inoculated percutaneously. Under otherwise identical experimental conditions the rate of infection for steel plates (75%) was significantly higher than that for titanium plates (35%) (p < 0.05).
TL;DR: Stable internal fixation can be achieved with two 2.0 AO titanium plates placed on each of the 'lateral' and the 'intermediate' columns of the wrist at an angle of 50 degrees to 70 degrees, and this gives good stability despite the tiny dimensions of the plates, and allows early function.
Abstract: Fractures of the distal end of the radius should be treated on the same principles as other fractures involving joints. Displaced articular fractures require open reduction to allow anatomical reconstruction of both the radiocarpal and the radio-ulnar joints. For extra-articular fractures with severe comminution and shortening this enables the radial length to be re-established achieving radio-ulnar congruency. Stable internal fixation can be achieved with two 2.0 AO titanium plates placed on each of the 'lateral' and the 'intermediate' columns of the wrist at an angle of 50 degrees to 70 degrees. This gives good stability despite the tiny dimensions of the plates, and allows early function. We report a series of 20 fractures treated by this method of internal fixation with satisfactory results in all.
TL;DR: The results show the excellent tribological features of alumina-ceramic-to-XLP implants, and also confirm the value of well-designed joint simulators for the evaluation of total joint replacements.
Abstract: We report the findings from independent prospective clinical and laboratory-based joint-simulator studies of the performance of ceramic femoral heads of 22.225 mm diameter in cross-linked polyethylene (XLP) acetabular cups. We found remarkable qualitative and quantitative agreement between the clinical and simulator results for the wear characteristics with time, and confirmed that ceramic femoral heads penetrate the XLP cups at only about half the rate of otherwise comparable metal heads. In the clinical study, 19 hips in 17 patients were followed for an average of 77 months. In the hip-joint simulator a similar prosthesis was tested for 7.3 million cycles. Both clinical and simulator results showed relatively high rates of penetration over the first 18 months or 1.5 million cycles, followed by a very much lower wear thereafter. Once an initial bedding-in of 0.2 mm to 0.4 mm had taken place the subsequent rates of penetration were very small. The initial clinical wear during bedding-in averaged 0.29 mm/year; subsequent progression was an order of magnitude lower at about 0.022 mm/year, lower than the 0.07 mm/year in metal-to-UHMWP Charnley LFAs. Our results show the excellent tribological features of alumina-ceramic-to-XLP implants, and also confirm the value of well-designed joint simulators for the evaluation of total joint replacements.
TL;DR: For knees with lesions of the medial femoral condyle of grades 3 or 4, arthroscopic debridement appears to be the treatment of choice with over half the patients free from pain after five years.
Abstract: In a prospective randomised trial 76 knees with isolated degenerative changes in the medial femoral condyle of grades 3 or 4 were treated by either arthroscopic debridement (40) or washout (36). All knees were followed up for at least one year and 58 for five years. The mean follow-up time was 4.5 years in the debridement group and 4.3 years in the washout group. At one year 32 of the debridement group and five of the washout group were painfree and at five years 19 of a total of 32 survivors in the debridement group and three of the 26 in the washout group were also free from pain. The mean improvement in a modified Lysholm score was 28 for the debridement group at one year and 21 at five years. In the washout group it was only 5 at one year and 4 at five years. For knees with lesions of the medial femoral condyle of grades 3 or 4, arthroscopic debridement appears to be the treatment of choice with over half the patients free from pain after five years.
TL;DR: Delayed physical examination after inversion injury of the ankle gives information of diagnostic quality which is equal to that of arthrography, and causes little discomfort to the patient.
Abstract: We studied the merits of physical examination after inversion injury of the ankle in 160 consecutive patients. They had an explanatory operation if they had a positive arthrogram and/or positive signs on a delayed physical examination. To determine the interobserver variation in delayed physical examination, five different examiners were asked to give independent assessment of the injury. Those with limited clinical experience produced more accurate results when physical examination was performed at five days after the injury, rather than within 48 hours. The specificity and sensitivity of delayed physical examination for the presence or absence of a lesion of an ankle ligament were found to be 84% and 96%, respectively. The interobserver agreement for the delayed physical examination of the ankle was good (kappa values 0.5, 0.6, 0.6 and 1.0). Delayed physical examination gives information of diagnostic quality which is equal to that of arthrography, and causes little discomfort to the patient.
TL;DR: The findings suggest that AO 'type' and the presence or absence of articular displacement are measured with high consistency when classification of distal radial fractures is undertaken by experienced observers.
Abstract: We sought to quantify agreement by different assessors of the AO classification for distal fractures of the radius. Thirty radiographs of acute distal radial fractures were evaluated by 36 assessors of varying clinical experience. Our findings suggest that AO 'type' and the presence or absence of articular displacement are measured with high consistency when classification of distal radial fractures is undertaken by experienced observers. Assessors at all experience levels had difficulty agreeing on AO 'group' and especially AO 'subgroup'. To categorize distal radial fractures according to joint displacement and AO type is simple and reproducible. Our study examined only whether distal radial fractures could be consistently classified according to the AO system. Validation of the classification as a predictor of outcome will require a prospective clinical study.
TL;DR: It is concluded that in patients with a rupture of one or more of the lateral ankle ligaments after an inversion injury, an impingement occurs between the medial malleolus and the medial facet of the talus.
Abstract: After a severe ankle sprain the incidence of residual complaints, particularly on the medial side of the joint, is high. We studied a consecutive series of 30 patients who had operative repair of acute ruptures of lateral ligaments. During operation, arthroscopy revealed a fresh injury to the articular cartilage in 20 ankles, in 19 at the tip and/or anterior distal part of the medial malleolus as well as on the opposite medial facet of the talus. In six patients, a loose piece of articular cartilage was found. We conclude that in patients with a rupture of one or more of the lateral ankle ligaments after an inversion injury, an impingement occurs between the medial malleolus and the medial facet of the talus. Patients with a lesion of the lateral ankle ligament caused by a high-velocity injury (a faulty landing during jumping or running) had a higher incidence of macroscopic cartilage damage (p < 0.01), medially-located pressure pain (p = 0.06) and medially-located complaints at one-year follow-up (p = 0.02) than those with low-velocity injury (a stumble).
TL;DR: The initial results suggest that the floating radial-head prosthesis may be suitable for the early or delayed treatment of Mason type-III fractures and more complex injuries involving the radial head.
Abstract: We report our experience over seven years with a floating radial-head prosthesis for acute fractures of the radial head and the complications which may result from such injury. The prosthesis has an integrated articulation which allows change of position during movement of the elbow. We present the results in 12 patients with a minimum follow-up of two years. Five prostheses had been implanted shortly after injury with an average follow-up of 49 months and seven for the treatment of sequelae with an average follow-up of 43 months. All prostheses have performed well with an improved functional score (modified from Broberg and Morrey 1986). We have not experienced any of the complications previously reported with silicone radial-head replacement. Our initial results suggest that the prosthesis may be suitable for the early or delayed treatment of Mason type-III fractures and more complex injuries involving the radial head.
TL;DR: Treatment with reamed nailing is associated with a significantly lower time to union and a reduced requirement for a further operation, and unreamed nailing should not be used in the treatment of the common Tscherne C1 tibial fracture.
Abstract: We performed a prospective, randomised study on 50 patients with Tscherne C1 tibial diaphyseal fractures comparing treatment with reamed and unreamed intramedullary nails. Our results show that reamed nailing is associated with a significantly lower time to union and a reduced requirement for a further operation. Unreamed nailing should not be used in the treatment of the common Tscherne C1 tibial fracture.
TL;DR: It is concluded that latissimus dorsi transfer can be effective in restoring shoulder function after massive irreparable tears of the rotator cuff.
Abstract: We treated 12 shoulders in ten patients with irreparable rotator-cuff tears by transfer of the latissimus dorsi. There were nine men and one woman. Their average age was 64.0 years and the average follow-up was 35.6 months (26 to 42). The results were excellent in four shoulders, good in four, fair in one, and poor in three. Active forward flexion improved from a preoperative average of 99 degrees to a postoperative average of 135 degrees. Osteoarthritic changes appeared in five shoulders and proximal migration of the humeral head progressed in six. EMG revealed that nine of the 12 transferred muscles showed activity which was synergistic with the supraspinatus on external rotation with abduction. We conclude that latissimus dorsi transfer can be effective in restoring shoulder function after massive irreparable tears of the rotator cuff.
TL;DR: In this article, the distribution of compressive "stress" within cadaver intervertebral discs, using a pressure transducer mounted in a 1.3 mm diameter needle, was investigated.
Abstract: We investigated the distribution of compressive ‘stress’ within cadaver intervertebral discs, using a pressure transducer mounted in a 1.3 mm diameter needle. The needle was pulled along the midsagittal diameter of a lumbar disc with the face of the transducer either vertical or horizontal while the disc was subjected to a constant compressive force. The resulting ‘stress profiles’ were analysed in order to characterise the distribution of vertical and horizontal compressive stress within each disc. A total of 87 discs from subjects aged between 16 and 87 years was examined.Our results showed that age-related degenerative changes reduced the diameter of the central hydrostatic region of each disc (the ‘functional nucleus’) by approximately 50%, and the pressure within this region fell by 30%. The width of the functional annulus increased by 80% and the height of compressive ‘stress peaks’ within it by 160%. The effects of age and degeneration were greater at L4/L5 than at L2/L3, and the posterior annulus ...
TL;DR: It is suggested that irradiation may cause an alteration in the bone matrix of allograft bone, but provided it is used in situations in which loading is within its elastic region, then failure should not occur.
Abstract: There have been conflicting reports on the effects of gamma irradiation on the material properties of cortical allograft bone. To investigate changes which result from the method of preparation, test samples must be produced with similar mechanical properties to minimise variations other than those resulting from treatment.
We describe a new method for the comparative measurement of bone strength using standard bone samples. We used 233 samples from six cadavers to study the effects of irradiation at a standard dose (28 kGy) alone and combined with deep freezing. We also investigated the effects of varying the dose from 6.8 to 60 kGy (n = 132).
None of the treatments had any effect on the elastic behaviour of the samples, but there was a reduction in strength to 64% of control values (p < 0.01) after irradiation with 28 kGy. There was also a dose-dependent reduction in strength and in the ability of the samples to absorb work before failure
We suggest that irradiation may cause an alteration in the bone matrix of allograft bone, but provided it is used in situations in which loading is within its elastic region, then failure should not occur.
TL;DR: Ilizarov circular fixation is an ideal method of treatment for high-energy fractures of the tibial plateau when extensive dissection and internal fixation are contraindicated due to trauma to the soft tissue, deficiency of bone stock, and bony comminution.
Abstract: We treated 24 patients with high-energy fractures of the tibial plateau by the Ilizarov fixator and transfixion wires. Eleven fractures were open, and 20 patients had complex injuries. Twelve were treated by ligamentotaxis and percutaneous fixation, seven by limited open reduction and five by extensive open reduction. All were followed for at least 24 months. All the fractures united, with an average time to healing of 14.4 weeks. Thirteen patients achieved full extension and 13 more than 110° of flexion. Twenty-two knees were stable. Fifteen patients walked normally and the rest with only a slight limp. All but two knees had an articular step-off of less than 4 mm and all had normal axial alignment except two. There were no cases of postoperative skin infection, osteomyelitis or septic arthritis. Ilizarov circular fixation is an ideal method of treatment for these fractures when extensive dissection and internal fixation are contraindicated due to trauma to the soft tissue, deficiency of bone stock, and bony comminution.
TL;DR: In this paper, a randomised prospective trial was conducted to compare a cemented unipolar prosthesis (Thompson) with an expensive bipolar prosthesis in the treatment of displaced intracapsular fractures of the hip in patients over 80 years of age.
Abstract: We performed a randomised prospective trial to compare a cemented unipolar prosthesis (Thompson) with a cemented bipolar prosthesis (Monk) in the treatment of displaced intracapsular fractures of the hip in patients over 80 years of age. Patients with a mental test score of less than 5/13 were excluded but the mortality was still about 30% at one year in both groups. We therefore feel that subjective criteria such as the level of pain and the return to the preinjury state are of paramount importance. Two years after operation there was no statistical difference between the rate of complications in the two groups. After adjusting for confounding factors such as differences in the level of function before injury between the groups, the degree of return to the preinjury state was significantly greater (p = 0.04) when using the unipolar prosthesis, which is one-quarter of the price of the bipolar. We cannot therefore justify the use of an expensive bipolar prosthesis in patients over 80 years of age.
TL;DR: There is not enough evidence in the literature to conclude that any form of pharmacological thromboprophylaxis decreases the death rate after total hip replacement, and guidelines which recommend their routine use to prevent death after hip replacement are not justified.
Abstract: The recommendation that patients having a total hip replacement should receive pharmacological thromboprophylaxis is based on the belief that fatal pulmonary embolism is common, and that prophylaxis will decrease the death rate. To investigate these assumptions we performed a meta-analysis of all studies on hip replacement which included information about death or fatal pulmonary embolism. A total of 130 000 patients was included. The studies were so varied in content and quality that the results of our analysis must be interpreted with some caution. The fatal pulmonary embolism rate was 0.1% to 0.2% even in patients who received no prophylaxis. This is an order of magnitude lower than that which is generally quoted, and therefore the potential benefit of prophylaxis is small and may not justify the risks. To balance the risks and benefits we must consider the overall death rate. This was 0.3% to 0.4%, and neither heparin nor any other prophylactic agent caused a significant decrease. Our study demonstrates that there is not enough evidence in the literature to conclude that any form of pharmacological thromboprophylaxis decreases the death rate after total hip replacement. For this reason guidelines which recommend their routine use to prevent death after hip replacement are not justified.
TL;DR: Although in this study osteochondral fractures fixed with PGA rods healed reliably, there were frequent, significant foreign-body reactions and Caution is needed when considering the use of PGA fixation devices in vulnerable regions such as the knee.
Abstract: Foreign-body reaction to polyglycolide (PGA) implants has been described in man. Many animal experiments have verified the mechanical properties of fixation devices made from PGA, but a significant foreign-body reaction has not been described. We studied the effect of PGA rods in 12 sheep with standardised osteochondral fractures of the medial femoral condyle fixed with uncoloured, self-reinforced PGA rods (Biofix). Radiographs were taken at intervals ranging from two weeks to two years, and the sheep were killed at intervals ranging from six to 24 months. All knees were examined histologically. Eleven of the 12 fractures healed radiologically and histologically. Moderate to severe osteolysis was seen at four to six weeks with maximum changes at 12 weeks in ten animals. Six knees showed fistula-like connections between the implant site and the joint space. Three developed synovitis, one with inflammatory changes involving the whole cartilage and one with destruction of the medial condyle. Although in our study osteochondral fractures fixed with PGA rods healed reliably, there were frequent, significant foreign-body reactions. Caution is needed when considering the use of PGA fixation devices in vulnerable regions such as the knee.
TL;DR: The afferent pathways of discogenic low-back pain have not been fully investigated as mentioned in this paper, but it has been hypothesised that this pain was transmitted mainly by sympathetic afferent fibres in the L2 nerve root, and in 33 patients they used selective local anaesthesia of this nerve.
Abstract: The afferent pathways of discogenic low-back pain have not been fully investigated. We hypothesised that this pain was transmitted mainly by sympathetic afferent fibres in the L2 nerve root, and in 33 patients we used selective local anaesthesia of this nerve. Low-back pain disappeared or significantly decreased in all patients after the injection. Needle insertion provoked pain which radiated to the low back in 23 patients and the area of skin hypoalgesia produced included the area of pre-existing pain in all but one. None of the nine patients with related sciatica had relief of that component of their symptoms. Our findings show that the main afferent pathways of pain from the lower intervertebral discs are through the L2 spinal nerve root, presumably via sympathetic afferents from the sinuvertebral nerves. Discogenic low-back pain should be regarded as a visceral pain in respect of its neural pathways. Infiltration of the L2 nerve is a useful diagnostic test and also has some therapeutic value.