The etiology of osteonecrosis of the hip may have a genetic basis. The interaction between certain risk factors and a genetic predisposition may determine whether this disease will develop in a particular individual.The rationale for use of joint-sparing procedures in the treatment of this disease i

Nontraumatic osteonecrosis of the femoral head: ten years later.

BackgroundA rupture of the entire fibers of the anterior cruciate ligament leads to knee instability due to increased anterior tibial translation and increased internal tibial rotation. The influence of isolated deficiency of the anteromedial or posterolateral bundle of the anterior cruciate ligament on the resulting knee kinematics have not yet been reported.HypothesisTransection of the anteromedial bundle will lead to increased anterior tibial translation at 90°. Transection of the posterolateral bundle will show an increased anterior tibial translation as well as a combined rotatory instability at 30°.Study DesignControlled laboratory study.MethodsKinematics of the intact knee were determined in response to a 134-N anterior tibial load and a combined rotatory load of 10 N·m valgus and 4 N·m internal tibial rotation using a robotic/universal force moment sensor testing system. Subsequently, the fibers of the anteromedial and posterolateral bundle were resected in an alternating order and the new transla...

The Role of the Anteromedial and Posterolateral Bundles of the Anterior Cruciate Ligament in Anterior Tibial Translation and Internal Rotation

Dislocation remains the leading early complication of total hip arthroplasty; surgical approach and implant positioning have been recognized as factors influencing total hip arthroplasty stability. We describe a total hip arthroplasty technique done through a single, tissue sparing anterior approach that allows implantation of the femoral and acetabular components without detaching or sectioning any of the muscles and tendons around the hip joint. A series of 437 consecutive, unselected patients who had 494 primary total hip arthroplasty surgeries done through an anterior approach on an orthopaedic table from September 1996 to September 2004 was reviewed. There were 54 hybrid and 442 uncemented hips in the 437 patients (57 bilateral). The average patient age was 64 years. Radiographic analysis showed an average abduction angle of 42°, with 96% in the range of 35° to 50° abduction. The average cup anteversion was 19° with 93% within the target range of 10° to 25°. Postoperative leg length discrepancy averaged 3 ± 2 mm (range, 0-26 mm). Three patients sustained dislocations for an overall dislocation rate of 0.61%, and no patients required revision surgery for recurrent dislocation. There were 17 operative complications, including one deep infection, three wound infections, one transient femoral nerve palsy, three greater trochanter fracture, two femoral shaft fractures four calcar fractures, and three ankle fractures. Operative time averaged 75 minutes (range 40-150 minutes), and the average blood loss was 350 mL (range, 100-1300 mL). The mean hospital stay was 3 days (range, 1-17 days). The anterior approach on the orthopaedic table is a minimally invasive technique applicable to all primary hip patients. This technique allows accurate and reproducible component positioning and leg-length restoration and does not increase the rate of hip dislocation.

Single-incision anterior approach for total hip arthroplasty on an orthopaedic table : The treatment of osteoarthritis of the hip 1920

A complete review of the literature disclosed that there were 42 reports of 2025 hips treated by either core decompression (1206 hips) or nonoperative management (819 hips), excluding electrical stimulation, for osteonecrosis of the femoral head. The peer-reviewed published reports included general surveys, prospective studies, and multicenter studies, but excluded case reports. Satisfactory clinical results were reported in 63.5% of hips in 24 studies of core decompression and in 22.7% of hips in 21 studies of nonoperative management. When looking at only precollapse hips, there were 71% versus 34.5% good results, respectively. Recalculation excluding reports by the 4 centers that do the most core decompressions (and report the best results) showed a clinical success rate for core decompression of 53% versus 22.7% for the nonoperatively treated group. Investigators of multiple studies have reported that nonoperative management leads to extremely poor results. Core decompression has been reported to have a notable effect on the natural history and clinical progression in early stages of osteonecrosis of the femoral head. In view of the limitations of this data, further clarification of this effect only can be obtained by large prospective randomized studies.

Core decompression versus nonoperative management for osteonecrosis of the hip.

Background: Minimally invasive total hip arthroplasty has stirred substantial controversy with regard to whether it provides superior outcomes compared with total hip arthroplasty performed through longer incisions The orthopaedic literature is deficient in well-designed scientific studies to support the clinical superiority of this approach The objective of this study was to compare the results of a single mini-incision approach with those of a standard-incision total hip arthroplasty in the early postoperative period

Methods: Two hundred and nineteen patients (219 hips) admitted for unilateral total hip arthroplasty between December 2003 and June 2004 were randomized to undergo surgery through a short incision of ≤10 cm or a standard incision of 16 cm All patients were blinded to the size of the incision for the duration of the hospital stay The anesthetic, analgesic, and postoperative physiotherapy protocols were standardized, with the staff also blinded to the technique used A single surgeon, who had performed more than 300 short-incision hip replacements prior to the start of this study and who performs an average of 415 primary total hip replacements a year, performed all procedures through a single-incision posterior approach using a cementless cup and cemented stem

Results: The two groups were matched for age, grade according to the system of the American Society of Anesthesiologists, and body mass index No significant difference was detected with respect to postoperative hematocrit, blood transfusion requirements, pain scores, or analgesic use We found no difference in early walking ability or length of hospital stay and no difference in component placement, cement-mantle quality, or functional outcome scores at six weeks The patient variables significantly associated with a probability of early discharge independent of incision length were patient age and preoperative hemoglobin levels (p < 005) The surgical scars contracted significantly over six weeks (p < 005) but by a similar proportion of 11% to 12% in both groups

Conclusions: Minimally invasive total hip arthroplasty performed through a single-incision posterior approach by a high-volume hip surgeon with extensive experience in less invasive approaches to the hip is safe and reproducible However, it offers no significant benefit in the early postoperative period compared with a standard incision of 16 cm As it is not known whether lower-volume and less-experienced surgeons can achieve similar results, the mini-incision technique merits further study before wide dissemination and implementation of this family of surgical approaches can be recommended

Level of Evidence: Therapeutic Level I See Instructions to Authors for a complete description of levels of evidence

A minimal-incision technique in total hip arthroplasty does not improve early postoperative outcomes. A prospective, randomized, controlled trial.

Background: Knee kinematics and in situ forces resulting from anterior cruciate ligament reconstructions with 2 femoral tunnel positions were evaluated.Hypothesis: A graft placed inside the anatomical footprint of the anterior cruciate ligament will restore knee function better than a graft placed at a position for best graft isometry.Study Design: Controlled laboratory study.Methods: Ten cadaveric knees were tested in response to a 134-N anterior load and a combined 10-N·m valgus and 5-N·m internal rotation load. A robotic universal force-moment sensor testing system was used to apply loads, and resulting kinematics were recorded. An active surgical robot system was used for positioning tunnels in 2 locations in the femoral notch: inside the anatomical footprint of the anterior cruciate ligament and a position for best graft isometry. The same quadrupled hamstring tendon graft was used for both tunnel positions. The 2 loading conditions were applied.Results: At 30° of knee flexion, anterior tibial transl...

Varying femoral tunnels between the anatomical footprint and isometric positions: effect on kinematics of the anterior cruciate ligament-reconstructed knee.

This prospective study compares a mini-incision technique and traditional posterior approach for total hip arthroplasty (THA). Thirty-three patients who had undergone a mini-incision THA were matched by diagnosis, gender, average age, and preoperative Harris Hip Score (HHS) to 33 patients who had undergone THA using the traditional posterior approach. The average length of the incision for group 1 was 11.7 cm (range, 7.3–13.0) and for group 2 was 20.2 cm (range, 14.8–26.0). At the 3-month follow-up, patients in the mini-incision group had significant improvement in limp ( P P P P P

Mini-incision technique for total hip arthroplasty with navigation

Background: We are not aware of any clinical studies in the literature comparing the results of vascularized and nonvascularized fibular grafting for the treatment of osteonecrosis of the femoral head. The purpose of this study was to compare the clinical results of free vascularized fibular grafting with those of nonvascularized fibular grafting.

Methods: Two hundred patients (220 hips) with osteonecrosis of the femoral head were treated with free vascularized fibular grafting at the University of Pittsburgh Medical Center, and ninety-nine patients (123 hips) were treated with nonvascularized fibular grafting at the Kyungpook National University Hospital in Korea. From these populations, two groups of fifty hips each, followed for a minimum of three years (average, five years), were matched by the stage, size, and etiology of the lesion and by the mean preoperative Harris hip score. A retrospective case-control study of these groups was then performed to compare the postoperative Harris hip scores as well as the prevalences of radiographic progression and collapse of the femoral head following free vascularized fibular grafting with those measures following nonvascularized fibular grafting.

Results: The mean Harris hip score improved for 70% of the hips treated with free vascularized fibular grafting: seventeen hips (34%) were rated excellent, fourteen (28%) were rated good, nine (18%) were rated fair, and ten (20%) were rated poor. The mean Harris hip score improved for 36% of the hips treated with nonvascularized fibular grafting: five hips (10%) were rated excellent; nine (18%), good; sixteen (32%), fair; and twenty (40%), poor. The rate of survival at seven years for the Stage-I and II hips (precollapse) was 86% after treatment with free vascularized fibular grafting compared with 30% after nonvascularized fibular grafting.

Conclusions: The results of this study strongly suggest that vascularized fibular grafting is associated with better clinical and radiographic results.

Level of Evidence: Therapeutic study, Level III-2 (retrospective cohort study). See Instructions to Authors for a complete description of levels of evidence.

Vascularized compared with nonvascularized fibular grafting for the treatment of osteonecrosis of the femoral head.

Sixty-five patients (88 hips) who received free vascularized fibula grafting for treatment of osteonecrosis of the femoral head at the University of Pittsburgh Medical Center, were followed for at least 3 years (average followup, 5.5 years; range, 3-7 years). There were 46 men and 19 women with an average age of 37 years (range, 20-52 years). All patients were evaluated using history, physical examination, Harris Hip Score, anteroposterior and lateral radiographs, and magnetic resonance images. The classification system of Steinberg et al (1995) was used to stage the disease. At final evaluation, 31 hips (35.2%) were rated excellent (Harris Hip Score > 90 points, minimal or no pain), 30 hips (34.1%) were rated good (Harris Hip Score 80-89 points, slight pain), seven hips (8%) were rated fair (Harris Hip Score 70-79, slight or moderate pain), and 20 hips (22.7%) were rated poor (Harris Hip Score < 70, pain). Twenty hips in 17 patients required total hip arthroplasty. In the remaining hips, the disease apparently arrested and the contour of the femoral head was preserved. Kaplan-Meier survivorship analyses showed that the probability of conversion to total hip arthroplasty within an average of 5.5 years after free vascularized fibula grafting was 28% for Stage II hips and 38% for Stages III and IV hips. The hip survival rate for subgroups at 5.5 years was 100% for Stages IC and IIA, 94% for Stage IIB, 50% for Stage IIC, 80% for Stage IIIB, 58% for Stage IIIC, 72% for Stage IVA, and 58% for Stage IVB. Free vascularized fibula grafting is a reliable operation and can preserve hip function and diminish pain successfully.

Free vascularized fibula grafting for the treatment of osteonecrosis of the femoral head.

Background Gross trunnion failure (GTF) is a rare complication in total hip arthroplasty (THA) reported across a range of manufacturers. Specific lots of the Stryker low friction ion treatment (LFIT) anatomic cobalt chromium alloy (CoCr) V40 femoral head were recalled in August 2016. In part, the recall was based out of concerns for disassociation of the femoral head from the stem and GTF. Methods We report on 28 patients (30 implants) with either GTF (n = 18) or head-neck taper corrosion (n = 12) of the LFIT CoCr femoral head and the Accolade titanium-molybdenum-zirconium-iron alloy femoral stems. All these cases were associated with adverse local tissue reactions requiring revision of the THA. Results In our series, a conservative estimate of the incidence of failure was 4.7% (n = 636 total implanted) at 8.0 ± 1.4 years from the index procedure. Failures were associated with a high-offset 127° femoral stem neck angle and increased neck lengths; 43.3% (13 of 30) of the observed failures included implant sizes outside the voluntary recall (27.8% [5 of 18] of the GTF and 75.0% [8 of 12] of the taper corrosion cases). Serum cobalt and chromium levels were elevated (cobalt: 8.4 ± 7.0 μg/mL; chromium: 3.4 ± 3.3 μ/L; cobalt/chromium ratio: 3.7). The metal artifact reduction sequence magnetic resonance imaging demonstrated large cystic fluid collections typical with adverse local tissue reactions. During revision, a pseudotumor was observed in all cases. Pathology suggested a chronic inflammatory response. Impending GTF could be diagnosed based on aspiration of black synovial fluid and an oblique femoral head as compared with the neck taper on radiographs. Conclusion In our series of the recalled LFIT CoCr femoral head, the risk of impending GTF or head-neck taper corrosion should be considered as a potential diagnosis in a painful LFIT femoral head and Accolade titanium-molybdenum-zirconium-iron alloy THA with unknown etiology. Almost half of the failures we observed included sizes outside of the voluntary recall.

Anton Plakseychuk

Papers

Varying femoral tunnels between the anatomical footprint and isometric positions: effect on kinematics of the anterior cruciate ligament-reconstructed knee.

Mini-incision technique for total hip arthroplasty with navigation

Vascularized compared with nonvascularized fibular grafting for the treatment of osteonecrosis of the femoral head.

Free vascularized fibula grafting for the treatment of osteonecrosis of the femoral head.

Trunnion Failure of the Recalled Low Friction Ion Treatment Cobalt Chromium Alloy Femoral Head