Background: Massive tears of the tendons of the rotator cuff cause atrophy and fatty degeneration of the rotator cuff muscles and painful loss of function of the shoulder. Repair of massive rotator cuff tears is often followed by retears of the tendons, additional muscular degeneration, and a poor clinical outcome. The purposes of this study were to determine whether a new method of repair of rotator cuff tendons can yield a lower retear rate and a better clinical outcome than previously reported methods, to assess the muscular changes following repair of massive tears of the musculotendinous units, and to correlate findings on magnetic resonance imaging with the clinical results.

Methods: Twenty-nine massive rotator cuff tears involving complete detachment of at least two tendons were repaired operatively with use of a new laboratory-tested technique in a prospective study. At least two years (average, thirty-seven months; range, twenty-four to sixty-one months) postoperatively, twenty-seven patients were evaluated clinically and with magnetic resonance imaging to determine the clinical outcome, the integrity of the repair, and the condition of the rotator cuff muscles.

Results: The age and gender-adjusted Constant score improved from an average of 49 percent preoperatively to an average of 85 percent postoperatively, corresponding to a subjective shoulder value of 78 percent of that of a normal shoulder. Pain-free flexion improved from an average of 92 degrees to an average of 142 degrees, and abduction improved from an average of 82 degrees to an average of 137 degrees. Pain decreased and performance of activities of daily living improved significantly (p < 0.05). The seventeen patients who had a structurally successful repair all had an excellent clinical outcome. Muscle atrophy could not be reversed except in successfully repaired supraspinatus musculotendinous units. Fatty degeneration increased in all muscles.

Conclusions: The method of repair of massive rotator cuff tears that was used in this study yielded a comparatively low retear rate and good-to-excellent clinical results; however, the repair did not result in substantial reversal of muscular atrophy and fatty degeneration. Retears occurred more often in patients who had had a shorter interval between the onset of the symptoms and the operation (p < 0.05). Patients who had a retear had improvement of the shoulder compared with the preoperative state, but they had less improvement than did those who had a successful repair.

The Results of Repair of Massive Tears of the Rotator Cuff

Background: Good functional results have been reported for arthroscopic repair of rotator cuff tears, but the rate of tendon-to-bone healing is still unknown. Our hypothesis was that arthroscopic repair of full-thickness supraspinatus tears achieves a rate of complete tendon healing equivalent to those reported in the literature with open or mini-open techniques.

Methods: Sixty-five consecutive shoulders with a chronic full-thickness supraspinatus tear were repaired arthroscopically in sixty-five patients with use of a tension-band suture technique. Patients ranged in age from twenty-nine to seventy-nine years. The average duration of follow-up was twenty-nine months. Fifty-one patients (fifty-one shoulders) had a computed tomographic arthrogram, and fourteen had a magnetic resonance imaging scan, performed between six months and three years after surgery. All patients were assessed with regard to function and the strength of the shoulder elevation.

Results: The rotator cuff was completely healed and watertight in forty-six (71%) of the sixty-five patients and was partially healed in three. Although the supraspinatus tendon did not heal to the tuberosity in sixteen shoulders, the size of the persistent defect was smaller than the initial tear in fifteen. Sixty-two of the sixty-five patients were satisfied with the result. The Constant score improved from an average (and standard deviation) of 51.6 ± 10.6 points preoperatively to 83.8 ± 10.3 points at the time of the last follow-up evaluation (p < 0.001), and the average University of California at Los Angeles score improved from 11.5 ± 1.1 to 32.3 ± 1.3 (p < 0.001). The average strength of the shoulder elevation was significantly better (p = 0.001) when the tendon had healed (7.3 ± 2.9 kg) than when it had not (4.7 ± 1.9 kg). Factors that were negatively associated with tendon healing were increasing age and associated delamination of the subscapularis or infraspinatus tendon. Only ten (43%) of twenty-three patients over the age of sixty-five years had completely healed tendons (p < 0.001).

Conclusions: Arthroscopic repair of an isolated supraspinatus detachment commonly leads to complete tendon healing. The absence of healing of the repaired rotator cuff is associated with inferior strength. Patients over the age of sixty-five years (p = 0.001) and patients with associated delamination of the subscapularis and/or the infraspinatus (p = 0.02) have significantly lower rates of healing.

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

Arthroscopic repair of full-thickness tears of the supraspinatus : does the tendon really heal?

As currently implemented, magnetic resonance imaging (MRI) relies on the protons of water molecules in tissue to provide the NMR signal. Protons are, however, notoriously difficult to image in some biological environments of interest, notably the lungs and lipid bilayer membranes such as those in the brain. Here we show that 129Xe gas can be used for high-resolution MRI when the nuclear-spin polarization of the atoms is increased by laser optical pumping and spin exchange. This process produces hyperpolarized 129Xe, in which the magnetization is enhanced by a factor of about 10(5). By introducing hyperpolarized 129Xe into mouse lungs we have obtained images of the lung gas space with a speed and a resolution better than those available from proton MRI or emission tomography. As xenon (a safe general anaesthetic) is rapidly and safely transferred from the lungs to blood and thence to other tissues, where it is concentrated in lipid and protein components, images of the circulatory system, the brain and other vital organs can also be obtained. Because the magnetic behaviour of 129Xe is very sensitive to its environment, and is different from that of 1H2O, MRI using hyperpolarized 129Xe should involve distinct and sensitive mechanisms for tissue contrast.

Biological magnetic resonance imaging using laser-polarized 129Xe

Magnetic resonance images of the shoulders of ninety-six asymptomatic individuals were evaluated to determine the prevalence of findings consistent with a tear of the rotator cuff. The scans were reviewed independently by two diagnostic radiologists who are experienced in the interpretation of magnetic resonance images of the shoulder. The over-all prevalence of tears of the rotator cuff in all age-groups was 34 per cent (thirty-three). There were fourteen full-thickness tears (15 per cent) and nineteen partial-thickness tears (20 per cent). The frequency of full-thickness and partial-thickness tears increased significantly with age (p < 0.001 and 0.05, respectively). Twenty-five (54 per cent) of the forty-six individuals who were more than sixty years old had a tear of the rotator cuff: thirteen (28 per cent) had a full-thickness tear and twelve (26 per cent) had a partial-thickness tear. Of the twenty-five individuals who were forty to sixty years old, one (4 per cent) had a full-thickness tear and six (24 per cent) had a partial-thickness tear. Of the twenty-five individuals who were nineteen to thirty-nine years old, none had a full-thickness tear and one (4 per cent) had a partial-thickness tear. Magnetic resonance imaging identified a high prevalence of tears of the rotator cuff in asymptomatic individuals. These tears were increasingly frequent with advancing age and were compatible with normal, painless, functional activity. The results of the present study emphasize the potential hazards of the use of magnetic resonance imaging scans alone as a basis for the determination of operative intervention in the absence of associated clinical findings.

/pdf/abnormal-findings-on-magnetic-resonance-images-of-1f2jkc4h42.pdf

Abnormal findings on magnetic resonance images of asymptomatic shoulders

Magnetic resonance imaging (MRI) has rapidly become an important tool in clinical medicine and biological research. Its functional variant (functional magnetic resonance imaging; fMRI) is currently...

/pdf/the-neural-basis-of-the-blood-oxygen-level-dependent-3asa5fi62j.pdf

The neural basis of the blood-oxygen-level-dependent functional magnetic resonance imaging signal.

Spin-lattice relaxation in the rotating frame (T1rho) dispersion spectroscopy and imaging were used to study normal and enzymatically degraded bovine articular cartilage. Normal specimens demonstrate significant T1rho "dispersion" (approximately 60 to approximately 130 ms) in the 100 Hz to 9 kHz frequency range. Proteoglycan-degraded specimens have 33% greater T1rho values than collagen-degraded or normal samples. T1rho-weighted images reveal structure not found in conventional T1- or T2-weighted images. Our results suggest that T1rho measurements are selectively sensitive to proteoglycan content. The potential of this method in distinguishing the early degenerative changes in cartilage associated with osteoarthritis is discussed.

T1ρ‐relaxation in articular cartilage: Effects of enzymatic degradation

Preliminary results from in vivo sodium MRI of human patellar articular cartilage are presented. Sodium images generated of an in vitro bovine patella clearly distinguish the region of proteoglycan depletion from the region of healthy cartilage. This provides the first evidence that sodium imaging may be used to detect changes due to osteoarthritis in vivo. The process of optimizing imaging time and signal-to-noise ratio, as well as potential implications in the detection of osteoarthritic change, are discussed.

Sodium MRI of human articular cartilage in vivo

Sensitivity of MRI to proteoglycan depletion in cartilage: comparison of sodium and proton MRI.

Objective:To evaluate the interobserver and intraobserver agreement for both treatment plan and fracture classification of tibial plateau fractures using plain films alone and with computed tomography (CT) scansDesign:Prospective study to assess the impact of an advanced radiologic study on the agr

Impact of CT scan on treatment plan and fracture classification of tibial plateau fractures

MR imaging was performed through the carpal tunnel in 18 wrists of nine normal volunteers and compared with cryomicrotome sections from cadaver wrists. MR reliably imaged the flexor retinaculum and carpal bones and thus defined the borders of the carpal tunnel. In all cases the median nerve was seen as an ovoid structure of moderate signal intensity and was easily distinguished from the flexor tendons of the hands running in the carpal tunnel. The tendons were separated from each other by their tendon sheaths, and this allowed for identification of the various tendons. Anatomic variations encountered in the normal volunteers included anomalous positioning of the origin of the lumbrical muscles within the carpal tunnel in two, persistent median arteries in two, and interposition of the median nerve between the flexor pollicis longus and the superficial flexor tendon to the index finger in one. Preliminary observations in 10 wrists of patients with carpal tunnel syndrome include segmental and diffuse swelling of the median nerve in six, distortion of the nerve in one, and thickening of the tendon sheaths in one. We conclude that MR imaging accurately and reliably displays the normal anatomy of the carpal tunnel and can detect morphologic changes in patients with carpal tunnel syndrome.

https://www.ajronline.org/doi/pdfplus/10.2214/ajr.148.2.307

J B Kneeland

Papers

T1ρ‐relaxation in articular cartilage: Effects of enzymatic degradation

Sodium MRI of human articular cartilage in vivo

Sensitivity of MRI to proteoglycan depletion in cartilage: comparison of sodium and proton MRI.

Impact of CT scan on treatment plan and fracture classification of tibial plateau fractures

MR imaging of the carpal tunnel: normal anatomy and preliminary findings in the carpal tunnel syndrome