Anatomical evaluation of the superficial medial collateral ligament distal tibial attachment of the knee.

This study aimed to evaluate the superficial medial collateral ligament distal tibial attachment (sMCL-dTA) morphologically and morphometrically. Seventeen unpaired formalin-fixed cadaveric knees were used. The sMCL was divided into anterior and posterior sections in the paracoronal plane along the midline of the sMCL. The distance from the medial edge of the tibial plateau and the joint line to the proximal margin, center, and distal margin of the sMCL-dTA and the length of the sMCL-dTA were measured in the anterior section, respectively. The sMCL-dTA was histologically observed in the posterior section with hematoxylin and eosin and Masson's trichrome staining. The distance from the medial edge of the tibial plateauto the proximal margin, center, and distal margin of the sMCL-dTA were 38.1 ± 4.2, 49.7 ± 4.4, and 61.5 ± 5.1 mm, respectively. The perpendicular distance from the joint line to the proximal margin, center, and distal margin of the sMCL-dTA were 36.1 ± 4.0, 47.4 ± 4.2, and 59.1 ± 4.8 mm, respectively. The length of the sMCL-dTA was 23.6 ± 3.2 mm. Histologically, the sMCL-dTA was formed by two layers of collagen fibers: the unidirectional fibrous layer and the multidirectional fibrous layer. The respective thicknesses of the two layers both decreased distally. The anatomical location, the length, and the attachment morphology of sMCL-dTA have been clarified using human cadaveric knees. Anatomical data in the present study contribute to the quality of surgery associated with sMCL-dTA.

Range of Motion Measurements of the Hip Joint Are Useful in Screening for Acetabular Dysplasia in Healthy Young Japanese Women.

The purpose of this study is to clarify whether a hip range of motion (ROM) measurement is useful in screening for early hip osteoarthritis with acetabular dysplasia (AD). Subjects were 58 healthy Japanese women volunteers (21.1 ± 0.7 (20 - 22)). We evaluated a total of 116 hip joints in these 58 cases. Sharp angle and centeredge angle were 44.1° ± 3.1° (37.0° - 51.5°) and 30.7°± 6.2° (19.5° - 47.0°), respectively. AD was present in 47.4%, but there were no severe cases. First, we compared the ROM of the hip joints with AD (AD group) and without AD (control group) according to the Mann-Whitney U test. Extension angles and external rotation angles in the AD group were significantly smaller than in the control group (18.9°± 6.1° VS. 22.1°± 4.2°, p= 0.01636, 26.3°± 8.9° VS. 34.1°± 8.8°, p= 0.001362, respectively). Next, we evaluated the following factors associated with AD by logistic regression analysis after adjustment for age: flexion, extension and internal and external rotation angles of the hip joint. As a result, internal rotation and external rotation were extracted as related factors. The area under the ROC curve was determined to have a moderate accuracy (0.72996). Cut off values of internal rotation and external rotation angles were 50 degrees and 35 degrees, respectively. Our findings suggest that ROM measurement of the internal and external rotation angles would be useful as a screening for AD in healthy young Japanese women without symptoms.

Effects of adipose-derived cell supplementation on tendon-bone healing in a rat model of chronic rotator cuff tear with suprascapular nerve injury.

OBJECTIVE: To investigate the effect of adipose-derived cells (ADCs) on tendon-bone healing in a rat model of chronic rotator cuff tear (RCT) with suprascapular nerve (SN) injury. METHODS: Adult rats underwent right shoulder surgery whereby the supraspinatus was detached, and SN injury was induced. ADCs were cultured from the animals' abdominal fat. At 6 weeks post-surgery, the animals underwent surgical tendon repair; the ADC (+ve) group (n = 18) received an ADC injection, and the ADC (-ve) group (n = 18) received a saline injection. Shoulders were harvested at 10, 14, and 18 weeks and underwent histological, fluorescent, and biomechanical analyses. RESULTS: In the ADC (+ve) group, a firm enthesis, including dense mature fibrocartilage and well-aligned cells, were observed in the bone-tendon junction and fatty infiltration was less than in the ADC (-ve) group. Mean maximum stress and linear stiffness was greater in the ADC (+ve) compared with the ADC (-ve) group at 18 weeks. CONCLUSION: ADC supplementation showed a positive effect on tendon-bone healing in a rat model of chronic RCT with accompanying SN injury. Therefore, ADC injection may possibly accelerate recovery in massive RCT injuries.

Effect of suprascapular nerve injury on muscle and regenerated enthesis in a rat rotator cuff tear model.

BACKGROUND: Massive rotator cuff tears (RCTs) are complicated by muscle atrophy, fibrosis, and intramuscular fatty degeneration, which are associated with postoperative tendon-to-bone healing failure and poor clinical outcomes. We evaluated muscle and enthesis changes in large tears with or without suprascapular nerve (SN) injury in a rat model. METHODS: Sixty-two adult Sprague-Dawley rats were divided into SN injury (+) and SN injury (-) groups (n=31 each), comprising tendon (supraspinatus [SSP]/infraspinatus [ISP]) and nerve resection and tendon resection only cases, respectively. Muscle weight measurement, histological evaluation, and biomechanical testing were performed 4, 8, and 12 weeks postoperatively. Ultrastructural analysis with block face imaging was performed 8 weeks postoperatively. RESULTS: SSP/ISP muscles in the SN injury (+) group appeared atrophic, with increased fatty tissue and decreased muscle weight, compared to those in the control and SN injury (-) groups. Immunoreactivity was only positive in the SN injury (+) group. Myofibril arrangement irregularity and mitochondrial swelling severity, along with number of fatty cells, were higher in the SN injury (+) group than in the SN injury (-) group. The bone-tendon junction enthesis was firm in the SN injury (-) group; this was atrophic and thinner in the SN injury (+) group, with decreased cell density and immature fibrocartilage. Mechanically, the tendon-bone insertion was significantly weaker in the SN injury (+) group than in the control and SN injury (+) groups. CONCLUSIONS: In clinical settings, SN injury may cause severe fatty changes and inhibition of postoperative tendon healing in large RCTs. Level of evidence: Basic research, controlled laboratory study.

Posterior decentering of the humeral head in patients with arthroscopic rotator cuff repair.

BACKGROUND: In some patients with rotator cuff tear (RCT), the axial view of magnetic resonance imaging (MRI) shows subtle posterior decentering (PD) of the humeral head from the glenoid fossa. This is considered to result from a loss of centralization that is typically produced by rotator cuff function. There are few reports on PD in RCT despite the common occurrence of posterior subluxation in degenerative joint disease. In this study, we investigated the effect of PD in arthroscopic rotator cuff repair (ARCR). METHODS: We conducted a retrospective study of consecutive patients who underwent ARCR at our institute and were followed-up for at least 1 year. PD was identified as a 2-mm posterior shift of the humeral head relative to the glenoid fossa in the axial MRI view preoperatively. The tear size and fatty degeneration (FD, Goutallier classification) were also evaluated using preoperative MRI. Retears were evaluated through MRI at 1 year postoperatively. RESULTS: We included 135 shoulders in this study. Ten instances of PD (including seven retears) were observed preoperatively. Fifteen retears (three and 12 retears in the small/medium and large/massive tear groups, respectively) were observed postoperatively. PD was significantly correlated with tear size, FD, and retear occurrence (p<0.01 each). The odds ratio for PD in retears was 34.1, which was greater than that for tear size ≥3 cm and FD grade ≥3. CONCLUSIONS: We concluded that large tear size and FD contribute to the occurrence of PD. Furthermore, PD could be a predictor of retear after ARCR.

Novel susceptibility loci for steroid-associated osteonecrosis of the femoral head in systemic lupus erythematosus.

Osteonecrosis of the femoral head (ONFH) involves necrosis of bone and bone marrow of the femoral head caused by ischemia with unknown etiology. Previous genetic studies on ONFH failed to produce consistent results, presumably because ONFH has various causes with different genetic backgrounds and the underlying diseases confounded the associations. Steroid-associated ONFH (S-ONFH) accounts for one-half of all ONFH, and systemic lupus erythematosus (SLE) is a representative disease underlying S-ONFH. We performed a genome-wide association study (GWAS) to identify genetic risk factors for S-ONFH in patients with SLE. We conducted a two-staged GWAS on 636 SLE patients with S-ONFH and 95 588 non-SLE controls. Among the novel loci identified, we determined S-ONFH-specific loci by comparing allele frequencies between SLE patients without S-ONFH and non-SLE controls. We also used Korean datasets comprising 148 S-ONFH cases and 37 015 controls to assess overall significance. We evaluated the functional annotations of significant variants by in silico analyses. The Japanese GWAS identified 4 significant loci together with 12 known SLE susceptibility loci. The four significant variants showed comparable effect sizes on S-ONFH compared with SLE controls and non-SLE controls. Three of the four loci, MIR4293/MIR1265 [odds ratio (OR) = 1.99, P-value = 1.1 × 10-9)], TRIM49/NAALAD2 (OR = 1.65, P-value = 4.8 × 10-8) and MYO16 (OR = 3.91, P-value = 4.9 × 10-10), showed significant associations in the meta-analysis with Korean datasets. Bioinformatics analyses identified MIR4293, NAALAD2 and MYO16 as candidate causal genes. MIR4293 regulates a PPARG-related adipogenesis pathway relevant to S-ONFH. We identified three novel susceptibility loci for S-ONFH in SLE.

Neurotropin protects rotator cuff tendon cells from lidocaine-induced cell death.

BACKGROUND: Local anesthetics often are used in rotator cuff tears as therapeutic tools, although some cases have reported that they have detrimental effects. Neurotropin (NTP) is used widely in Japan as a treatment for various chronic pain conditions and is shown to have protective effects on cartilage and nerve cells. In this study, we investigated the protective effect of NTP against lidocaine-induced cytotoxicity. METHODS: Tenocytes from rotator cuff tendons were incubated with lidocaine, NTP, lidocaine with NTP, and a control medium. Cell viability was evaluated using the WST-8 assay. Cell apoptosis was detected via annexin V staining using flow cytometry. The expression of BCL-2 and cytochrome c, which are involved in the intrinsic mitochondrial pathway of apoptosis, was evaluated via Western blotting and immunohistochemical staining. RESULTS: In the cell viability assay, lidocaine decreased cell viability in a dose-dependent manner, and NTP did not affect cell viability. Moreover, NTP significantly inhibited the cytotoxic effect of lidocaine. The flow cytometry analysis showed that lidocaine significantly induced apoptosis in tenocytes, and NTP considerably inhibited this lidocaine-induced apoptosis. Western blotting experiments showed that lidocaine decreased the protein expression of BCL-2, and that NTP conserved the expression of BCL-2, even when used with lidocaine. Immunohistochemical staining for cytochrome c showed that 0.1% lidocaine increased cytochrome c-positive cells, and NTP suppressed lidocaine-induced cytochrome c expression. CONCLUSIONS: NTP suppresses lidocaine-induced apoptosis of tenocytes by inhibiting the mitochondrial apoptotic pathway. Intra-articular/ bursal injection of NTP with lidocaine could protect tenocytes in rotator cuff tendons against lidocaine-induced apoptosis.

Incidence of Re-Dislocation/Instability After Arthroscopic Bankart Repair: Analysis via Telephone Interviews.

INTRODUCTION: Current advances in arthroscopic surgery have led to good outcomes for arthroscopic Bankart repair (ABR) for recurrent anterior shoulder dislocation. However, recent studies have reported recurrence rates of 4%-19% after ABR. In our survey conducted from February 2002 to December 2010, the post-ABR re-dislocation rate was 8.8%. In 2011, we began performing the ABR with open Bristow (B) procedure or Remplissage (R) procedure in patients with large glenoid or humeral head bone defects and in patients who play collision sports. Therefore, the present study is the second series evaluating the incidence of re-dislocation and instability after recurrent anterior shoulder dislocation. METHOD: Surgery was performed for 84 cases of shoulder instability from January 2011 to August 2017. After excluding 7 open surgeries, 6 reoperations, and 2 patients with multidirectional instability, telephone interviews were conducted with 69 patients. The average follow-up duration was 46.9 months (range, 13-92 months). RESULT: ABR alone was performed 61 patients; the B procedure was added for 3 patients, and the R procedure was added for 5 patients. Telephone interviews were conducted with 61 patients. There were no cases of re-dislocation or reoperation. Four patients who underwent only ABR experienced postoperative instability, but not to the extent that their daily lives were affected. CONCLUSION: This study showed that the addition of R or B technique to ABR for recurrent anterior shoulder dislocation resulted in a 0% re-dislocation rate.

Functional and Structural Outcomes After Retears of Arthroscopically Repaired Large and Massive Rotator Cuff Tears.

BACKGROUND: Most studies have shown acceptable clinical results in patients with large or massive tears treated by arthroscopic rotator cuff repair (ARCR); however, the effects of retears after surgery in these patients remain unknown. PURPOSE: To evaluate functional and structural outcomes after retears of large and massive rotator cuff tears treated by ARCR. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: A total of 196 consecutive patients with large to massive rotator cuff tears underwent physical examination and magnetic resonance imaging before and after ARCR at 6, 12, and 24 months. Of these, 9 patients were lost at 6 months after surgery. Therefore, 187 patients were followed up for 24 months after surgery; 148 patients showed no postsurgical ruptures. Consequently, the remaining 39 patients with postsurgical ruptures were included in this study (mean age at surgery, 64.2 ± 8.7 years). Functional outcome measures comprised the University of California, Los Angeles (UCLA) and Japanese Orthopaedic Association (JOA) scores. Structural outcome measures consisted of the global fatty degeneration index (GFDI), mediolateral tear size, and residual tendon attachment area as evaluated by our own scoring system. RESULTS: The mean UCLA and JOA scores significantly improved from 16.3 ± 3.9 and 63.2 ± 10.7 preoperatively to 27.9 ± 5.5 (P < .0001) and 84.5 ± 9.4 (P < .0001) at final follow-up, respectively. The mean mediolateral tear size (P = .03, .02, and .02, respectively) and residual tendon attachment area (P = .04, .03, and .04, respectively) significantly improved from preoperatively to 6, 12, and 24 months postoperatively. The correlation analysis between the functional and structural variables confirmed significant associations between the residual tendon attachment area, the JOA and UCLA scores at 24 months postoperatively, and the preoperative GFDI (r = -0.81 to 0.78). CONCLUSION: The residual tendon attachment area after a retear was significantly larger at 24 months after surgery than before surgery. In addition, significant associations were confirmed between preoperative fatty degeneration, the residual tendon attachment area, and functional outcomes after a retear. These results may explain why functional outcomes significantly improved even after retears in this series.

Midterm Functional and Structural Outcomes of Large/Massive Cuff Tears Treated by Arthroscopic Partial Repair.

BACKGROUND: Previous studies have shown good clinical outcomes in patients with irreparable large or massive rotator cuff tears treated using arthroscopic partial repair (APR); however, few studies have evaluated both functional and structural outcomes in these patients. PURPOSE: To evaluate both functional and structural outcomes in patients with large or massive rotator cuff tears treated using APR. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Between March 2009 and November 2016, a total of 30 patients underwent APR because of the irreparability of their large or massive rotator cuff tears during surgery. Of these patients, 24 completed the minimum 24-month follow-up (mean, 61.8 ± 27.1 months; range, 24-112 months) and were included in this study. Functional outcome measures included the Japanese Orthopaedic Association (JOA) and University of California Los Angeles (UCLA) scores and the visual analog scale for pain. Structural outcome measures comprised preoperative fatty degeneration, mediolateral tear size, residual tendon attachment area, and glenohumeral (GH) arthritic changes evaluated on magnetic resonance imaging scans or plain radiographs before and after surgery. Functional and structural outcomes were evaluated preoperatively, at 3 months postoperatively, and at the final follow-up. RESULTS: The JOA scores for all patients significantly improved from 67.9 ± 11.3 preoperatively to 85.4 ± 15.6 postoperatively (P < .0001). Similarly, the UCLA scores significantly improved from 15.8 ± 4.20 preoperatively to 29 ± 6.69 at final follow-up postoperatively (P < .0001). The mediolateral tear size were significantly decreased at 3 months postoperatively (P < .001) and at the final follow-up (P < .001). Compared with preoperative scores, the novel score evaluating the residual tendon attachment area improved from 3.08 ± 0.46 to 3.54 ± 0.41 (P < .001) after surgery overall, although it significantly deteriorated from 3 months postoperatively to the final follow-up. GH osteoarthritis progressed in 6 patients (25%). Patients who developed osteoarthritis had lower JOA and UCLA scores than did those who did not (JOA, P = .010; UCLA, P = .037). CONCLUSION: In irreparable large or massive rotator cuff tears treated using APR, functional outcome improved after surgery. Although the residual tendon attachment area improved, functional outcome after APR corresponded to the GH alterations at the midterm follow-up. Longer-term follow-up is needed to further elucidate the effect of APR on clinical outcomes in these patients.

Clinical outcome in patients with hand lesions associated with complex regional pain syndrome after arthroscopic rotator cuff repair.

BACKGROUND: Complex regional pain syndrome (CRPS)-related hand lesions are one of the complications following arthroscopic rotator cuff repair (ARCR). This study aimed to investigate the clinical outcomes of patients with CRPS-related hand lesions following ARCR. METHODS: Altogether, 103 patients with ARCR were included in this study (mean age, 63.6±8.2 years; 66 males and 37 females; follow-up period, preoperative to 12 months postoperative). Clinical assessment included the Japanese Orthopaedic Association (JOA) score, University of California, Los Angeles (UCLA) score, Constant score, 36-item short form health survey (SF-36) score, and Quick Disabilities of the Arm, Shoulder, and Hand (QuickDASH) score from preoperative to 12 months postoperatively. The patients were either assigned to the CRPS group or non-CRPS group depending on CRPS diagnosis until the final follow-up, and clinical outcomes were then compared between the groups. RESULTS: Of 103 patients, 20 (19.4%) had CRPS-related hand lesions that developed entirely within 2 months postoperatively. Both groups showed significant improvement in JOA, UCLA, and Constant scores preoperatively to 12 months postoperatively (P<0.001). Comparisons between the two groups were not significantly different, except for SF-36 "general health perception" (P<0.05) at 12 months postoperatively. At final follow-up, three patients had residual CRPS-related hand lesions with limited range of motion and finger edema. CONCLUSIONS: CRPS-related hand lesions developed in 19.4% of patients following ARCR. Shoulder or upper-limb function improved in most cases at 12 months, with satisfactory SF-36 patient-based evaluation results. Patients with residual CRPS-related hand lesions at the last follow-up require long-term follow-up.

Saphenous Nerve Entrapment Neuropathy After Closed Tibial Fracture: A Case Report.

CASE: A 43-year-old man who underwent intramedullary nailing for a closed tibial fracture developed saphenous nerve entrapment neuropathy. He developed severe medial leg pain, which was worse on walking or standing, 2 years postoperatively. Surgical neurolysis resulted in complete pain relief and functional recovery of the limb without recurrence of symptoms. CONCLUSION: Clinicians should consider several etiologies in the diagnostic evaluation of a patient with chronic pain after limb trauma. If a patient complains of lower extremity pain after intramedullary fixation of closed fractures of the tibial shaft, the possibility of saphenous nerve entrapment neuropathy should be considered.

Preoperative hyaluronic acid injection modulates postoperative functional outcome in patients undergoing arthroscopic rotator cuff repair.

BACKGROUND: Arthroscopic rotator cuff repair (ARCR) generally yields acceptable clinical results. Hyaluronic acid (HA), a high-molecular-weight polysaccharide, is present in the extracellular matrix of soft connective tissue and synovial fluid, and its injection is known to significantly improve pain and clinical outcomes after rotator cuff injury. Some studies have described the role of HA injections as conservative therapy for rotator cuff tears. Since the subacromial bursa is believed to be the main source of shoulder pain in rotator cuff tears, subacromial injection is frequently used before surgery; however, its relationship with the clinical outcome after surgery remains unclarified. Therefore, we aimed to examine effects of preoperative subacromial HA injection on postoperative clinical outcome in patients with ARCR. METHODS: Ninety-eight patients were divided into a HA injection group and a non-injection group. The functional outcome measured was the University of California, Los Angeles (UCLA) score. Univariate analysis was performed to obtain variables with p values less than 0.1; we then used propensity score analysis, adjusting for pre- and post-operative confounding factors. RESULTS: The UCLA scores of all patients significantly improved 1 year postoperatively (PO) (p < 0.05). Subacromial HA injections were performed in patients with worse preoperative function. Univariate analysis showed significantly greater improvements in the injection group than in the non-injection group in terms of preoperative UCLA score, trauma, diabetes mellitus, UCLA score 3 months PO, abduction strength 4 months PO, and internal rotation (IR) strength 6 and 12 months PO. Propensity score analysis demonstrated that UCLA scores 3 months PO and IR strength 12 months PO in the injection group were significantly greater than those in the non-injection group. There were no significant differences in postoperative re-tear rates between the groups. In sub-analysis of the injection group, propensity scores showed that concurrent use of local anesthetics did not affect the data, suggesting that HA was effective. CONCLUSION: Subacromial injection was administered to patients with worse function before ARCR. Propensity score analysis successfully demonstrated that functional outcome after surgery was improved in patients who were administered this injection compared with patients who were not administered this injection before surgery.

Effects of Estrogen-Deficient State on Rotator Cuff Healing.

BACKGROUND: Rotator cuff retears after surgical repair are a concern, despite advances in operative techniques, but few studies have investigated the effects of the estrogen-deficient state on tendon-to-bone healing at the repair site. PURPOSE: We evaluated the effect of the estrogen-deficient state on tendon-to-bone healing after rotator cuff repair in an ovariectomized rat model. STUDY DESIGN: Controlled laboratory study. METHODS: Female Sprague Dawley rats underwent detachment and immediate repair of the supraspinatus tendon. Surgery was performed in 24 rats at 4.5 weeks of age 17 weeks after ovariectomy (OVX group) and in 24 age-matched control rats without ovariectomy (control group). Animals were sacrificed at 2, 4, 8, and 12 weeks after surgery for biomechanical and histological evaluations of reattachment. Bone mineral density (BMD) at the insertion site and cancellous bone in the humeral head was assessed by micro-computed tomography. RESULTS: BMD was significantly lower both at the insertion site and in cancellous area in the OVX group than in the control group at weeks 2 to 12. Ultimate load to failure, ultimate stress, linear stiffness, and the Young modulus were significantly lower in the OVX group than in the control group at 2 and 4 weeks, but the difference was no longer significant at 8 and 12 weeks. At 2 and 4 weeks, relatively immature granulation tissue was observed in the OVX group compared with the control group. At 8 and 12 weeks after surgery, there were differences in the tendon-bone interface in the 2 groups: Direct insertion with well-established chondroid tissue was seen in the control group, and indirect insertion without chondroid tissue was seen in the OVX group. Consistently, the amount of chondroid tissue was greater and collagen organization was better in the control group than in the OVX group. Cells expressing cathepsin K were significantly more numerous both at the insertion site and in cancellous bone in the OVX group than in the control group. CONCLUSION: The estrogen-deficient state by ovariectomy, compared with control rats, led to decreased biomechanical properties and poor development of chondroid tissue that influenced the repair of the tendon insertion after surgery. CLINICAL RELEVANCE: Agents that modulate bone metabolism might improve tendon-to-bone healing in patients with an estrogen-deficient state, such as postmenopausal women who undergo rotator cuff surgery.

Prognostic factors affecting clinical outcomes after arthroscopic rotator cuff repair: importance of functional recovery by 3 months after surgery.

BACKGROUND: To examine important factors that affect clinical outcomes following arthroscopic rotator cuff repair (ARCR). METHODS: Among 163 patients who underwent ARCR, we included 71 shoulders in 71 patients whose progress was monitored for > 2 years, postoperatively. We divided the patients into groups A (scores ≥ 83 points, 59 patients) and B (scores < 83 points, 12 patients) using the Japanese Orthopedic Association (JOA) score at 24 months. We then conducted univariate and multivariate analyses of pre- and postoperative (2 and 3 months, respectively) factors. RESULTS: The mean JOA score for all patients significantly improved from 63.7 ± 11.5 points preoperatively to 90.3 ± 9.6 points at 24 months postoperatively (P < 0.05). However, there were no significant between-group differences in the preoperative scores. In addition, there were no significant differences in the postoperative re-tear rate. Univariate analysis revealed that the range of motion (preoperative abduction and postoperative elevation, abduction, internal rotation, and external rotation), muscle strength (external rotation 3 months postoperatively), postoperative pain level [visual analog scale (VAS) maximum score, 10 points], partial repair, Cofield classification, and preoperative width were significant factors (P < 0.05 for all factors). Multivariate and receiver operating characteristic curve analyses showed that VAS at 2 months postoperatively and elevation at 3 months postoperatively were significant factors. CONCLUSIONS: To obtain a JOA score of ≥ 83 points at 24 months postoperatively, following ARCR, a postoperative VAS of < 5 points at 2 months and postoperative elevation of ≥ 110° at 3 months should be achieved.

Hand lesion after arthroscopic rotator cuff repair: Association with complex regional pain syndrome.

BACKGROUND: It is known that complex regional pain syndrome (CRPS) occurs after arthroscopic rotator cuff repair (ARCR); however, few studies have investigated this complication. Therefore, the purpose of the present study was to evaluate CRPS after ARCR. METHODS: A total of 182 patients who underwent ARCR were enrolled in this study. The average age of patients was 62.8 ± 10.0 years, with an average follow-up period of 21.5 ± 38.1 months. CRPS criteria outlined by the Ministry of Health, Labor, and Welfare study team for CRPS in Japan (MHLWJ) and International Association for the Study of Pain (IASP 2005) were utilized for diagnosis. There are two rating systems for the "clinical purpose" and "research purpose" in both criteria, respectively. Clinical outcomes, including Japanese Orthopedic Association (JOA) and University of California, Los Angeles scores, were evaluated using univariate and multivariate analysis. RESULTS: CRPS exclusively occurred in the hand of the operated limb, developing within 3 months of surgery. Two or more of the following symptoms were noted in patients with the hand lesion associated with CRPS: edema (93.4%), restricted range of motion (83.4%), hyperalgesia (30.1%), paridrosis (20.4%), and atrophic change (12.2%). Under these conditions, the incidences of CRPS were 24.2% (44/182) when evaluated by the MHLWJ rating system for the "clinical purpose;" 11% (22/182) by the MHLWJ rating system for the "research purpose;" 6% (11/182) by the IASP 2005 for the "clinical purpose;" and 0.5% (1/182) by the IASP 2005 for the "research purpose." Results of multivariate analysis demonstrated that "Function" in the JOA score was a risk factor for the development of CRPS after ARCR, when evaluated by a system for the "clinical purpose" of the MHLWJ. CONCLUSION: Following ARCR, CRPS-induced hand lesions occur more frequently than is generally believed, thereby suggesting that its impact on surgical outcomes should be clarified in the future.

Genome-wide Association Study of Idiopathic Osteonecrosis of the Femoral Head.

Idiopathic osteonecrosis of the femoral head (IONFH) is an ischemic disorder that causes bone necrosis of the femoral head, resulting in hip joint dysfunction. IONFH is a polygenic disease and steroid and alcohol have already known to increase its risk; however, the mechanism of IONFH remains to be elucidated. We performed a genome-wide association study using ~60,000 subjects and found two novel loci on chromosome 20q12 and 12q24. Big data analyses identified LINC01370 as a candidate susceptibility gene in the 20q12 locus. Stratified analysis by IONFH risk factors suggested that the 12q24 locus was associated with IONFH through drinking capacity. Our findings would shed new light on pathophysiology of IONFH.

Effect of Preoperative Fatty Degeneration of the Rotator Cuff Muscles on the Clinical Outcome of Patients With Intact Tendons After Arthroscopic Rotator Cuff Repair of Large/Massive Cuff Tears.

BACKGROUND: Fatty degeneration of the rotator cuff muscles is associated not only with postoperative retear but also with postoperative muscle weakness; therefore, fatty changes in the muscles may affect the clinical outcome even in patients with these tears who have intact tendons after arthroscopic rotator cuff repair (ARCR). PURPOSE: To evaluate the effect of fatty infiltration on the clinical outcome in patients with intact tendons after arthroscopic repair of large/massive cuff tears. STUDY DESIGN: Case-control study; Level of evidence, 3. METHODS: One hundred fifty-five consecutive patients with large/massive rotator cuff tears underwent ARCR. Of these, 55 patients (mean ± SD age, 64.4 ± 9.1 years) in whom intact tendons after surgery were confirmed with magnetic resonance imaging at final follow-up (mean ± SD, 2.5 ± 1.4 years) were included in this study. Depending on their University of California Los Angeles (UCLA) score at the final follow-up, they were assigned to either the unsatisfactory group (score ≤27; n = 12) or the satisfactory group (score >27; n = 43). Various clinical parameters affecting the clinical outcome were examined through univariate and multivariate analyses. RESULTS: The UCLA score of all patients significantly improved from 18.1 ± 4.4 points preoperatively to 29.8 ± 4.5 points postoperatively ( P < .0001). The mean preoperative UCLA scores were not significantly different between the satisfactory and unsatisfactory groups ( P = .39). Multivariate analysis showed that the preoperative Goutallier stages of the infraspinatus (odds ratio [OR], 8.87; 95% confidence interval [CI], 1.51-52.0; P = .016) and/or subscapularis (OR, 7.53; 95% CI, 1.58-35.9; P = .011) were significantly associated with outcome. Receiver operating characteristic curve analysis revealed a cutoff value of Goutallier stage 1 in both muscles, with area under the curve values of 0.79 (sensitivity 91% and specificity 51%) and 0.84 (sensitivity 100% and specificity 54%) in the infraspinatus and subscapularis, respectively. CONCLUSION: Preoperative fatty degeneration of the infraspinatus and/or subscapularis with Goutallier stage 2 or higher was significantly associated with worse outcome in patients with large/massive tears who had intact tendons after ARCR.

Risk factors for retear of large/massive rotator cuff tears after arthroscopic surgery: an analysis of tearing patterns.

BACKGROUND: Previous studies have evaluated the risk factors for retear of large/massive rotator cuff tears (RCTs) that were treated arthroscopically; however, most studies did not evaluate tear patterns. The present study hypothesized that postoperative risk factors are affected by the tearing patterns in large/massive cuff tears in patients undergoing arthroscopic rotator cuff repair (ARCR). METHODS: One hundred fifty patients with large/massive cuff tears underwent ARCR at our institution. Of these, 102 patients were enrolled in this study, with an average symptom duration of 36.3 ± 43.9 months and average age of 63.9 ± 9.4 years. According to the arthroscopic findings and magnetic resonance imaging (MRI), the 102 patients were divided into three groups based on the tendon location: anterosuperior tears (N = 59, group AS), posteosuperior tears (N = 21, group PS), and anteroposterior-extending tears (N = 22, group APE). Functional outcome was evaluated preoperatively and postoperatively using the Japanese Orthopedic Association (JOA) score and the University of California, Los Angeles (UCLA) score. Retear was evaluated with MRI at a minimum of 1 year after surgery, using Sugaya's classification; Types IV and V were considered postoperative retears. Factors affecting postoperative retear were examined with univariate and multivariate analyses. RESULTS: JOA/UCLA scores significantly improved postoperatively in the three groups (P < 0.01 for all). Postoperative retear was noted in 26 of 102 patients (25.5%) in this series: 10 patients in group AS (16.9%), 9 in group PS (42.9%), and 7 in group APE (31.8%). The retear rate was significantly higher in group PS than in the other two groups (P = 0.02). Multivariate analysis showed that decreased preoperative active external rotation range was a unique risk factor for postoperative retear in the PS and APE groups (95% confidence interval: 0.02-0.18, cut-off value: 25°, with an area under the curve of 0.90, P = 0.0025). CONCLUSIONS: Although multivariate analysis failed to detect significant risk factor for retear in patients with anterosuperior large/massive cuff tears who undergo ARCR, it demonstrated that active external rotation less than 25° before surgery is a significant risk factor in those with posterosuperior large/massive tears. This study may help surgeons understand the results of arthroscopic surgery in patients with large/massive tears.

A Case Report of an Acromioclavicular Joint Ganglion Associated with a Rotator Cuff Tear.

We report a case of subcutaneous ganglion adjacent to the acromioclavicular joint with massive rotator cuff tear [1-7]. An 81-year-old woman presented with a ganglion adjacent to the acromioclavicular joint that had first been identified 9 months earlier. The ganglion had recurred after having been aspirated by her local physician, so she was referred to our hospital. The puncture fluid was yellowish, clear and viscous. Magnetic resonance imaging identified a massive rotator cuff tear with multi- lobular cystic lesions continuous to the acromioclavicular joint, presenting the "geyser sign". During arthroscopy, distal clavicular resection and excision of the ganglion were performed together with joint debridement. At present, the ganglion has not recurred and the patient has returned to normal daily activity. In this case, the ganglion may have developed subsequent to the concomitant massive cuff tear, due to subcutaneous fluid flow through the damaged acromioclavicular joint.