Long-term outcomes of hemiarthroplasty using a smaller head combined with rotator cuff reconstruction in patients with cuff-tear arthropathy.

Background: Hemiarthroplasty (HHR) using a smaller head with rotator cuff reconstruction is a treatment option for cuff-tear arthropathy, offering advantages like facilitating rotator cuff-tear closure, increasing the lever arm of deltoid, and restoring function in irreparable cuff tears. This study aimed to evaluate the long-term outcomes of this procedure. Methods: A retrospective analysis was conducted for 91 shoulders undergoing HHR using a smaller head with rotator cuff reconstruction between May 2005 and September 2012. Surgery involved reducing the size of humeral head and performing rotator cuff reconstruction based on the site of the deficient rotator cuff. The study analyzed University of California, Los Angeles shoulder scores, Japanese Orthopaedics Association shoulder scores, range of motion, and postoperative radiographs. Results: Twenty-eight patients, divided into an elderly group (14 women, 2 men, mean age 74.5 ± 3.8 years) and a younger group (6 women, 6 men, mean age 63.5 ± 3.1 years) were followed up for a mean of 133.2 ± 14.1 months. No complications were reported. The clinical scores and range of motion significantly improved postoperatively and remained over 10 years. Radiographs revealed high incidence of glenoid wear (82.1%), bone resorption (43%) and cranial humeral head migration (54%), with no prosthesis loosening. Conclusion: We believe that HHR using a smaller head with rotator cuff reconstruction is a surgical technique that can maintain stable long-term outcomes in both elderly and younger individuals with cuff-tear arthropathy.

Correlation of suprascapular notch morphology with suprascapular nerve palsy: a 3D-computed tomography study.

Background: The morphology of the suprascapular (SS) notch is a very important factor in treatment of suprascapular nerve (SSN) palsy. Several studies have reported SS notch morphology in cadavers or using a three-dimensional computed tomography (3D-CT); however, none has reported the distribution of SS notch morphology according to the age group. In addition, the correlation between SS notch morphology and SSN palsy remains unclear. The purposes of this study were to investigate the morphological distribution of the SS notch by age group in a large population and to assess the relationship between SS notch morphology and SSN palsy. Methods: We studied the 3D-CT images of 1063 shoulders in 1009 patients (mean age, 60.8 years; age range, 14-96 years). There were 53 shoulders with SSN palsy and 1010 shoulders without SSN palsy. Morphology of the SS notch was classified by Rengachary's classification (types I-VI). Shoulders with types I-IV were classified into the nonossified superior transverse scapular ligament (STSL) group (group N) and those with types V and VI into the ossified STSL group (group O). Results: The Rengachary's classifications of the 1063 shoulders were as follows: type I: n = 113, 10.6%; type II: n = 313, 29.4%; type III: n = 383, 36.0%; type IV: n = 109, 10.3%; type V: n = 107, 10.0%; and type VI: n = 38, 3.6%. Mean age was significantly older in the ossified STSL group, and the age was <40 years for only two shoulders in this group. The Rengachary's classifications of the SSN palsy cases were as follows: type I: 7.5%, II: 24.5%, III: 34.0%, IV: 15.1%, V: 13.2%, and VI: 5.7%. There was no statistical difference in age and sex, Rengachary type, or ossification between SSN palsy and non-SSN palsy cases. Conclusions: Ossification of the STSL was significantly more common in older patients, which suggests age-related change. In addition, no relation was identified between narrow notch or ossification of the STSL with the onset of SSN palsy.

Coronal Hamate Fractures with Carpometacarpal Dislocation Treated Effectively Using Headless Compression Screws with Percutaneous Pinning Fixation by Using the 2-Directional Approach: A Report of 2 Cases.

CASE: Coronal shear fractures of the hamate are relatively rare injuries. Surgical intervention is recommended for displaced fractures. However, there is no established surgical procedure for the displaced coronal shear fractures of the hamate. Therefore, we present 2 cases of the displaced coronal hamate fracture with metacarpal dislocations, which were successfully managed with open reduction and internal fixation, using the headless compression screw by the 2-directional approach. CONCLUSION: Our procedure ensured that the screw's distal end captured the hamate hook, and the displaced bone fragments were reduced considerably in both cases.

The effect of the remplissage procedure on shoulder range of motion: a cadaveric study.

PURPOSE: The purpose of this in vitro biomechanical study was to assess the effects of the remplissage procedure for small- and large-sized Hill-Sachs lesions (HSLs) on shoulder range of motion (ROM) with a special interest in the apprehension position. METHODS: HSLs of 50% and 100% of the glenoid width were simulated in 7 cadaveric shoulders as small and large lesions, respectively, and the postoperative condition was reproduced by placing suture anchors on the articular surface and tying down the infraspinatus at the medial edge of the would-be lesion site. ROMs were measured in abduction, internal rotation, and external rotation with the humerus in the adducted and abducted position. In addition, the ROM was measured in the anterior apprehension position, in which 2 torques of external rotation and extension were applied simultaneously, and external rotation and horizontal extension ROMs were measured with the humerus in different abduction angles (20°, 40°, and 60°). RESULTS: For standard ROMs, the procedure for the 50% HSL maintained complete ROMs, whereas the procedure for the 100% HSL significantly decreased external rotation ROM with the humerus in both the adducted and abducted positions, as well as abduction ROM. In the apprehension position, remplissage for the 50% HSL decreased extension ROM with the humerus abducted to 40° and 60°. Remplissage for the 100% HSL significantly decreased both external and extension ROMs regardless of the humeral abduction angle. CONCLUSIONS: In the cadaveric model with an intact humeral head and the simulated postoperative condition, the remplissage procedure for a large HSL caused significant restrictions in ROM of abduction in the scapular plane and external rotation with the humerus in both adduction and abduction. It also caused significant restrictions in both external rotation and extension ROMs in the apprehension position. CLINICAL RELEVANCE: The indication for the remplissage procedure for the larger HSL should be considered carefully, especially for the competitive throwing athlete who needs exceptional external rotation ROM for optimal overhead throwing performance.

Tensile properties of a morphologically split supraspinatus tendon.

The supraspinatus tendon consists morphologically of two sub-regions, anterior and posterior. The anterior sub-region is thick and tubular while the posterior is thin and strap-like. The purpose of this study was to compare the structural and mechanical properties of the anterior and posterior sub-regions of the supraspinatus tendon. The supraspinatus tendons from seven human cadaveric shoulders were morphologically divided into the anterior and posterior sub-regions. Length, width, and thickness were measured. A servo-hydraulic testing machine (MTS Systems Corporation, Minneapolis, MN) was used for tensile testing. The maximal load at failure, modulus of elasticity and ultimate tendon stress were calculated. Repeated measures were used for statistical comparisons. The mean anterior tendon cross-sectional area was 47.3 mm(2) and the posterior was 32.1 mm(2) . Failure occurred most often at the insertion site: anterior (5/7) and posterior (6/7). All parameters of the anterior sub-region were significantly greater than those of the posterior sub-region. The moduli of elasticity at the insertion site were 592.4 MPa in the anterior sub-region and 217.7 MPa in the posterior (P = 0.01). The ultimate failure loads were 779.2 N in the anterior sub-region and 335.6 N in the posterior (P = 0.003). The ultimate stresses were 22.1 MPa in the anterior sub-region and 11.6 MPa in the posterior (P = 0.008). We recognized that the anterior and posterior sub-regions of the SSP tendon have significantly different mechanical properties. In a future study, we need to evaluate how best to repair an SSP tendon considering these region-specific properties.

Effect of humeral head rotation on bony glenohumeral stability.

BACKGROUND: The humeral head and glenoid cavity are not perfectly spherical, nor do they have matching radii of curvature. We hypothesized that glenohumeral stability is dependent on axial humeral rotation. METHODS: Seven cadaveric shoulders were investigated. For each test, the humeral head was translated relative to the glenoid in 2 directions (starting from neutral), anterior and anteroinferior. Contact forces and lateral humeral displacement were recorded. Joint stability was quantified using the stability ratio and energy to dislocation. The humerus was set in 60° of abduction for all tests. Testing was performed in neutral rotation and 60° of external rotation. FINDINGS: The force displacement curves differed between rotations. In both displacement directions, the peak translational force occurred with less displacement in neutral rotation than in external rotation. The stability ratio and energy to dislocation in the anteroinferior direction were greater than in the anterior direction for both rotation positions. While there were no significant differences in the stability ratio or energy to dislocation between rotation conditions at complete dislocation, the energy required to move the humeral head 10% of the glenoid width was significantly greater with the arm in neutral rotation. INTERPRETATION: The energy to dislocation, a new parameter of dislocation risk, and the stability ratio, indicate that the glenohumeral joint is more stable in the anteroinferior direction than the anterior direction. During initial displacement, axial rotation of the humeral head contributes to glenohumeral geometrical stability. However, humeral head rotation does not have a significant effect when looking at complete dislocation.

Transfer of teres minor with bone pedicle for irreparable posterior-superior rotator cuff tears.

BACKGROUND: The objectives of this study are to evaluate the clinical and radiographic mid- to long-term outcomes of patients treated by teres minor with bone pedicle transfer for irreparable massive rotator cuff tear and to investigate the limitations of this procedure. METHODS: Clinical outcomes were assessed by quantifying: the range of shoulder motion; a visual analog pain scale; the University of California, Los Angeles Shoulder Score (UCLA score); and the Disability of the Arm, Shoulder, and Hand (DASH) score. Radiographs were assessed for deterioration of the glenohumeral joint and upper migration of the humeral head. RESULTS: Eighteen patients with mean age of 66.9 years and mean follow-up of 74.4 months were included. The technique resulted in significant decrease in shoulder pain. The mean UCLA score improved from 10.3 points initially to 24.1 points at time of final follow-up. However, the postoperative results were classified as poor in 11 shoulders. The mean postoperative DASH score was 27.6 points. The mean active forward elevation significantly improved from 75.9° initially to 121.6° at time of final follow-up. In radiographic assessment, osteoarthritis of the glenohumeral joint progressed in 15 shoulders, and the upper migration of humeral head progressed in 14 shoulders. CONCLUSIONS: Aggravation of the glenohumeral joint and upper migration of the humeral head both progressed postoperatively at a high rate. Therefore, we conclude that this procedure should no longer be performed despite its relative simplicity.

Clinical outcomes of excision arthroplasty for Kienbock's disease.

We have carried out a replacement of the lunate in 12 patients with advanced Kienböck's disease, with excision of the lunate and insertion of an iliac bone flap wrapped into palmaris longus. The aims of this study were to determine the effect of this procedure for advanced Kienböck's disease. At a mean follow-up period of 45.3 months, the mean clinical score was excellent in all cases. Radiographically, progression of osteoarthritis (OA) in the radiocarpal joint was found in two patients. At follow-up, the X-ray findings indicated a reduced of osseous core in four patients. On the other hand, carpal height ratio showed no significant change at follow-up. Excision arthroplasty using a tendon ball with osseous core for advanced Kienböck's disease leads to OA progression in some cases. However, clinical results were excellent in all cases. Therefore, this current study provides effective therapeutic procedure for advanced Kienböck's disease.

Alterations of high-mannose type N-glycosylation in human and mouse osteoarthritis cartilage.

OBJECTIVE: The process of N-glycosylation is involved in the pathogenesis of various diseases. However, little is known about the contribution of changes in N-glycans in osteoarthritis (OA). The aim of this study was to identify the alterations in N-glycans in human OA cartilage, to characterize the messenger RNA (mRNA) expression of N-glycan biosynthesis enzyme genes (N-glycogenes) in mouse articular chondrocytes during cartilage degradation, and to analyze the relationship between altered N-glycan patterns and mechanisms of cartilage degradation. METHODS: Alterations in N-glycans were analyzed in human OA cartilage and degraded mouse cartilage by high-performance liquid chromatography and mass spectrometry. N-glycogene mRNA expression in mouse chondrocytes was measured using reverse transcription-polymerase chain reaction. To assess the relationship between the altered N-glycans and degradation of mouse cartilage, experiments involving either knockdown or overexpression of N-glycogenes were performed in mouse articular chondrocytes. RESULTS: Alterations in high-mannose type N-glycans were observed in both human OA cartilage and degraded mouse cartilage. The expression of ß1,2N-acetylglucosaminyltransferase I (GlcNAc-TI) mRNA, which converts high-mannose type N-glycans, was significantly increased in degraded mouse cartilage. Mouse chondrocytes with suppressed GlcNAc-TI expression had reduced levels of matrix metalloproteinase 13 (MMP-13) and ADAMTS-5 (aggrecanase 2) mRNA following stimulation with interleukin-1α (IL-1α). In contrast, mouse chondrocytes overexpressing GlcNAc-TI had increased levels of MMP-13 and ADAMTS-5 mRNA following stimulation with IL-1α. CONCLUSION: These findings indicate that alterations in high-mannose type N-glycans and N-glycogenes in chondrocytes correlate with the release of MMP-13 and ADAMTS-5 during cartilage degradation. These findings suggest that N-glycans play a crucial role in the initiation and progression of OA.

Palmar subluxation of the thumb carpometacarpal joint following the median nerve recurrent branch injury.

To our knowledge, the combination of a palmar subluxation of the thumb carpometacarpal (CMC) joint with low median nerve deficit followed by the recurrent branch injury is extremely rare. We present a case of the subluxation of the thumb CMC joint with low median nerve deficit.

Radial overgrowth after radial shortening osteotomies for skeletally immature patients with Kienböck's disease.

PURPOSE: We hypothesized that radial shortening osteotomy (radial shortening) for skeletally immature patients with Kienböck's disease would induce overgrowth of the radius. The purpose of this study was to determine the effect of radial shortening on radial growth in skeletally immature patients with Kienböck's disease and to clarify the relationship between the postoperative growth alterations and the clinical results. METHODS: Eight wrists of 8 skeletally immature patients with Kienböck's disease were treated with radial shortening. There were 3 boys and 5 girls, ranging in age from 11 to 18 (mean, 14) years old. All patients presented with open physis and negative ulnar variance. The length of the radial shortening equaled the amount of negative ulnar variance. Clinical assessment was based on the modified Nakamura scoring system. Radiographic assessment, including Lichtman's stages, ulnar variance, carpal height ratio, radial inclination, and volar tilt, was performed before surgery, immediately after surgery, and at follow-up. A difference in ulnar variance of more than 2 mm between these 3 measurements was considered to be overgrowth. Statistical comparisons were performed using paired t-tests. RESULTS: At a mean follow-up period of 69 months, the mean clinical score was 19.7 of 21 maximum points, with all wrists rated as excellent. Radiographically, no progression of Lichtman stage was found in any patient. At follow-up, the x-ray and magnetic resonance imaging findings indicated lunate revascularization in all patients. Four of the 8 had overgrowth in the operated radius. On the other hand, other radiographic parameters showed no significant changes at follow-up. The occurrence of postoperative radial overgrowth did not notably affect the clinical scores. CONCLUSIONS: The current results suggest the probability of overgrowth of the radius in skeletally immature patients with Kienböck's disease treated with radial shortening. The postoperative radial overgrowth after this osteotomy had no effect on clinical and other radiographic outcomes. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.