The Effect of Denosumab on Rotator Cuff Repair in Women Aged 60 and over with Osteoporosis: A Prospective Observational Study.

BACKGROUND: In previous studies, denosumab, a RANKL human monoclonal antibody used in osteoporosis treatment, has shown efficacy in tendon healing after rotator cuff repair. This prospective study investigated the effects of denosumab on tendon healing, re-tear rates, and clinical outcomes post rotator cuff repair in women with osteoporosis. METHOD: This was a prospective, observational study, employing propensity score matching for the control group. From March 2018 to March 2023, female patients over the age of 60 with normal bone density undergoing arthroscopic rotator cuff repair were selected as controls through propensity score matching (PSM) and compared with female patients of the same age group with osteoporosis who were receiving denosumab treatment. The control group was matched using 1-to-2 propensity score matching. Radiological examinations and functional outcomes were assessed preoperatively and at 6 months postoperatively. RESULTS: In the final analysis, the study comprised 34 patients in the denosumab treatment group (Group 1) and 68 patients in the control group (Group 2). The functional scores showed significant improvement at 6 months post-surgery in both groups. No significant difference in the functional scores was observed among the groups. The re-tear rate, defined according to Sugaya's classification (types IV and V) as re-tear, was slightly higher in Group 1 at 16.7% (6 of 34) compared to Group 2 at 11.7% (8 of 68), but the difference was not statistically significant (p = 0.469). The re-tear patterns, classified according to Rhee's classification, also showed no significant difference among the groups (Group 1: 2/4 of 6; Group 2: 4/4 of 8; p = 0.571). The occurrence of type I re-tear exhibited no significant difference between the two groups (5.9% vs. 5.9%; p = 1.000). CONCLUSIONS: The administration of denosumab following arthroscopic rotator cuff repair in women aged 60 and over with osteoporosis resulted in a re-tear rate that was similar to that observed in patients without osteoporosis. This result suggests that denosumab administration might be beneficial for rotator cuff healing, particularly in the context of osteoporosis, a known risk factor for increased retear rates. Therefore, comprehensive osteoporosis screening and treatment should be considered in conjunction with rotator cuff repair surgery in middle-aged women.

Reinforcement Techniques in Arthroscopic Repair of Large-to-Massive Rotator Cuff Tears: A Comparative Study of Superior Capsule Reconstruction and Patch Graft Augmentation.

Background: Large-to-massive rotator cuff tears (LMRCTs) present challenges in achieving successful repair due to factors such as muscle atrophy and tendon retraction. Arthroscopic rotator cuff repair (ARCR) with reinforcement techniques like superior capsule reconstruction (SCR) or patch graft augmentation (PGA) has emerged as a less invasive option to improve shoulder joint stability and prevent retear. This study aimed to compare the clinical and radiological outcomes of SCR and PGA as reinforcement techniques for the arthroscopic repair of LMRCTs. Methods: A single-center retrospective study was conducted on patients undergoing LMRCT repair between January 2019 and December 2021. Patients were divided into two groups: those receiving SCR (Group 1) and those receiving PGA (Group 2). Various clinical parameters including range of motion, functional scores, and radiological assessments were evaluated preoperatively and six months postoperatively. Results: Both SCR and PGA techniques demonstrated significant improvements in the range of motion and clinical scores postoperatively. However, Group 2 showed higher postoperative SST and UCLA scores compared to Group 1. Radiologically, there was a slightly higher retear rate in Group 2, although this was not statistically significant. Group 2 also had a shorter mean duration of surgery compared to Group 1. Conclusions: In the arthroscopic repair of LMRCTs, both SCR and PGA techniques exhibit favorable clinical and radiological outcomes. Despite the simplicity of PGA compared to SCR, it offers comparable results with a shorter surgical duration, making it a feasible reinforcement option for surgeons.

A Comparison of Clinical Outcomes in Rotator Cuff Re-Tear Patients Who Had Either an Arthroscopic Primary Repair or Arthroscopic Patch Augmentation for Large-to-Massive Rotator Cuff Tears.

BACKGROUND AND PURPOSE: Despite the prevalent incidence of re-tear following rotator cuff repair, there is a notable lack of comparative studies investigating the outcomes between patients with re-tear who underwent primary repair versus those who received patch augmentation for large-to-massive tears. We assessed clinical outcomes of these techniques through a retrospective, randomized controlled trial. METHODS: 134 patients diagnosed with large-to-massive rotator cuff tears from 2018 to 2021 underwent surgery; 65 had primary repair and 69 had patch augmentation. A total of 31 patients with re-tears were included, split into two groups; Group A (primary repair, 12 patients) and Group B (patch augmentation, 19 patients). Outcomes were evaluated using several clinical scales and MRI imaging. RESULTS: Most clinical scores improved postoperatively in both groups. No significant difference in clinical outcomes was observed between groups, except for pain visual analog scale (P-VAS) scores. P-VAS scores showed greater decrease in the patch-augmentation group, a statistically significant difference. CONCLUSIONS: for large-to-massive rotator cuff tears, patch augmentation led to greater decreases in pain than primary repair, despite similar radiographic and clinical results. Greater tuberosity coverage of the supraspinatus tendon footprint may impact P-VAS scores.

The Use of Intravenous Zoledronate May Reduce Retear Rate after Rotator Cuff Repair in Older Female Patients with Osteoporosis: A First In-Human Prospective Study.

The objective of this study was to demonstrate the effect of intravenous (IV) zoledronate administration on rotator cuff healing, retear rate, and clinical outcomes in osteoporotic patients who underwent arthroscopic rotator cuff repair (ARCR) compared with patients with normal bone densities. In this prospective nonrandomized comparative study with propensity score matching, 30 patients who were postoperatively administered IV zoledronate (5 mg) were enrolled as the study group. The control group was matched using 1-to-2 propensity score matching. Radiologic and functional outcomes were evaluated 6 months after surgery. The functional scores in both groups exhibited significant improvement 6 months after surgery. Compared with Group 1 (osteoporosis with IV zoledronate injection) Group 2 (normal bone density) showed significant improvement in their University of California, Los Angeles (UCLA) shoulder score and Constant Shoulder Score (CSS) at 6 months postoperatively. The range of motion improved in both groups at 6 months after surgery. The retear rates according to Sugaya's classification (IV and V) were 13.3% (4 of 30 patients) and 25% (15 of 60 patients) in Groups 1 and 2, respectively, which established a non-inferiority of Group 1 to the control group. The retear pattern according to Rhee's classification in Group 1 was type I in all cases, whereas eight cases of type I and seven cases of type II patterns were observed in Group 2, which was statistically insignificant between the groups. In conclusion, anti-osteoporotic drug use is beneficial for patients with osteoporosis to reduce the failure rate after an ARCR of length > 2 cm, especially in older female patients. Moreover, thorough scrutiny is required to detect osteoporosis in patients with rotator cuff tears, especially in female patients.

Calcific tendinitis of the shoulder in the Korean population: demographics and its relation with coexisting rotator cuff tear.

BACKGROUND: To evaluate the demographics, clinical and radiographic features of calcific tendinitis of the shoulder in the Korean population, specifically focusing on the incidence of coexisting rotator cuff tear. METHODS: Between October 2014 and January 2015, we performed a prospective multicenter study with 506 patients from 11 training hospitals in Korea. We collected data of demographics and radiographic analysis based on simple radiographs, clinical assessments based on visual analog scale (VAS) and the American Shoulder Elbow Surgeons (ASES) score, and treatment modalities that are used currently. We also evaluated coexisting rotator cuff tear by ultrasonography (US) or magnetic resonance imaging (MRI) images. RESULTS: There were 402 female patients (79%) with mean age of 55 years (range, 31-87 years). Mean duration of symptoms was 16 months. Mean size of calcific materials was 11.4 mm (range, 0-35 mm). Mean value of VAS and ASES scores were 6.5 (range, 1-10) and 47 (range, 8-95), respectively. Of 383 patients (76%), 59 (15%) had rotator cuff tear including 15 full-thickness tears on US or MRI. Patients with rotator cuff tears were significantly associated with older age, recurrent symptoms, menstrual disorders in females, and having undergone calcification removal surgery and rotator cuff repair (all p<0.05). CONCLUSIONS: This study reported demographic, radiographic, and clinical features of calcific tendinitis of the shoulder in Korean population, which were not different from those of Western population. Coexisting rotator cuff tear was found with 15% incidence in this large series, suggesting that further radiographic study to evaluate rotator cuff tear might be needed in some calcific tendinitis patients of older age and presenting with recurrent symptoms.

Clinical and Radiologic Outcomes of Combined Use of Biocomposite and PEEK Suture Anchors during Arthroscopic Rotator Cuff Repair: A Prospective Observational Study.

The aim of the current study was to evaluate the functional and radiologic outcomes of biocompatible non-absorbable PEEK (polyetheretherketone) and biocomposite (poly-L-lactic acid/poly(lactic-co-glycolic acid) 70% + ß-tricalcium phosphate) anchors, especially in terms of perianchor cyst formation during the first six months postoperatively. We prospectively analysed 29 patients who underwent arthroscopic rotator cuff repair between March and May 2019. Both PEEK and biocomposite suture anchors were used as lateral anchors in one body. Clinical outcomes were assessed using the shoulder range of motion (ROM), visual analogue scale (VAS) for pain and satisfactory score, American Shoulder and Elbow Surgeons (ASES) score, and Simple Shoulder Test (SST). All these were obtained in patients preoperatively at 3 and 6 months after surgery. The imaging evaluation included perianchor cyst formation, anchor absorption, repaired cuff integrity, and retear pattern. All functional outcomes significantly improved over time. The biocomposite anchor had a statistically significant tendency to form higher grades of fluid collection at 3 months after surgery. However, the perianchor cyst reduced by the sixth postoperative month. Six months postoperatively, the functional outcomes were improved after rotator cuff repair and similar degrees of perianchor cyst formation were observed, regardless of the suture anchor material used.

Mortality and cause of death in distal radius fracture patients: A longitudinal follow-up study using a national sample cohort.

The various harmful impacts of distal radius fractures (DRFs) may cause adverse effects. Although previous studies have reported the adverse effects of DRFs on mortality, most studies were performed in adults of advanced age and paid little attention to confounding factors of mortality. Furthermore, most of these studies investigated the overall impact of DRFs on mortality without differentiating the specified causes of death.The purpose of the present study was to estimate the risk of mortality in DRF patients according to the cause of death.Data from the Korean National Health Insurance Service-National Sample Cohort (NHIS-NSC) from 2002 to 2013 were collected. A total of 27,295 DRF participants who were 50 years or older were 1:4 matched with control participants for age, sex, income, and region of residence. The causes of death were grouped into 12 classifications.DRFs were not associated with increased overall mortality. The adjusted hazard ratio (HR) of mortality was 1.04 (95% confidence interval [CI] = 0.98-1.11, P = .237). The adjusted HR for mortality was not significantly different according to age. The odds ratio of overall mortality was 1.03 (95% CI = 0.97-1.11, P = .329).DRFs were not associated with a significant increase in mortality.

Can a Single Sagittal Magnetic Resonance Imaging Slice Represent Whole Fatty Infiltration in Chronic Rotator Cuff Tears at the Supraspinatus?

BACKGROUND: This study aimed to investigate whether fatty infiltration (FI) measured on a single sagittal magnetic resonance imaging (MRI) slice can represent FI of the whole supraspinatus muscle. METHODS: This study retrospectively reviewed the MRIs of 106 patients (age 50-79 years) divided into three rotator cuff tear-size groups: medium, large, and massive. Fat mass and muscle mass on all T1-weighted sagittal MRI scans (FA and MA) were measured. Of the total MRI scans, the Y-view was defined as the most lateral image of the junction of the scapular spine with the scapular body on the oblique sagittal T1-weighted image. Fat mass and muscle mass seen on this Y-view single slice were recorded as F1 and M1, respectively. Fat mass and muscle mass were also assessed on MRI scans lateral and medial to the Y-view. The means of fat mass and muscle mass on these three slices were recorded as F3 and M3, respectively. Average FI ratios (fat mass/muscle mass) of the three assessment methods (F1/M1, FA/MA, and F3/M3) were compared. Intraclass correlation coefficients (ICCs) were calculated for inter- and intraobserver reliability. RESULTS: ICCs showed higher reliability (> 0.8) for all measurements. F1/M1 values were not statistically different from FA/MA and F3/M3 values (p > 0.05), except in males with medium and large tears. F3/M3 and FA/MA were not statistically different. The difference between F1/M1 and FA/MA did not exceed 2%. CONCLUSIONS: A single sagittal MRI slice can represent the whole FI in chronic rotator cuff tears, except in some patient groups. We recommend measurement of FI using a single sagittal MRI slice, given the effort required for repeated measurements.

Chronic Open Infective Lateral Malleolus Bursitis Management Using Local Rotational Flap.

BACKGROUND: Using a sinus tarsi rotational flap is an uncommon approach to treating chronic open infective lateral malleolus bursitis. METHODS: We treated eight patients, including six males, using this approach. First, we debrided all the infected tissues and used a negative pressure wound closure system where needed. After acute infection had been controlled, the local rotational flap was used for cases where the wound could not be closed by a simple suture or bone exposure. The rotational flap was detached with a curved skin incision at the sinus tarsi next to the open wound and sutured to the defect, paying careful attention to the superficial peroneal nerve. The donor site was managed with a split-thickness skin graft. RESULTS: The patients' mean age was 74.1 years. Six patients had a wound after suppurative infection, but two patients had ulcer-type bursitis. Six patients demonstrated full flap healing, but two patients had venous congestion necrosis. CONCLUSION: A sinus tarsi rotational flap is a useful method to ensure healing and coverage of chronic open lateral malleolus bursitis, especially for small to medium wounds with cavity and bone exposure.

Preparation and in vivo evaluation of lecithin-based microparticles for topical delivery of minoxidil.

Minoxidil is widely used for treatment of androgenic alopecia. Commercial products containing minoxidil are usually in solution form. Repeated applications of minoxidil solution can lead to adverse effects such as skin irritation and horniness. The aims of this study were to prepare lecithin-based microparticle in minoxidil solution for enhancement of minoxidil topical delivery and skin protection and evaluate the ability of lecithin on in vitro delivery, in vivo hair growth, and skin trouble improvement compared to commercial minoxidil solution. In in vitro skin permeation study, minoxidil solution containing lecithin microparticle showed higher skin penetration rate and higher retention of drug inside the skin compared to minoxidil solution without lecithin. After topical application of minoxidil solutions with or without lecithin to C57BL/6 mice, minoxidil 5% solution containing lecithin microparticle showed hair re-growth as efficient as commercial product of minoxidil 5% solution. It also significantly improved skin troubles while commercial product presented horny substance and crust formation. Therefore, the lecithin-based microparticle in minoxidil 5% solution has good ability to promote hair growth without adverse effects.

Arthroscopically Assisted Coracoclavicular Fixation Using a Single Flip Button Device Technique: What Are the Main Factors Affecting the Maintenance of Reduction?

BACKGROUND: Among coracoclavicular (CC) fixation techniques, the use of flip button device was demonstrated to have successful outcomes with the advantage of being able to accommodate an arthroscopic procedure. PURPOSE: This study was conducted to investigate the factors associated with loss of fixation after arthroscopically assisted CC fixation using a single flip button device for acromioclavicular (AC) joint dislocations. MATERIALS AND METHODS: We enrolled a total of 47 patients (35 men and 12 women). Plain radiography was performed at a mean of 24 months postoperatively to evaluate the final radiological outcome. The primary outcome measure was a long-term reduction of the AC joint for at least 24 months. RESULTS: We found that 29 patients had a high quality reduction (61.7%) and 18 patients had a low quality reduction (38.3%) in initial postoperative CT findings. Our study showed that the duration (5 days) from injury to treatment and the quality of initial postoperative reduction were significantly associated with the maintenance of reduction at final follow-up. CONCLUSION: Our study showed that maintaining stable reduction after arthroscopically assisted CC fixation using a single flip button device technique is difficult especially in patients who received delayed treatment or whose initial reduction quality was poor.

The Anatomical Relationship Between the Dorsal Cutaneous Branch of the Ulnar Nerve and the Ulnar Styloid Process with Variations in Forearm Position.

BACKGROUND: There are significant variations in the anatomy of the dorsal cutaneous branch of the ulnar nerve (DCBUN). The DCBUN is at risk for iatrogenic injury during surgeries around the ulnar side of the wrist. The purpose of this study was to demonstrate the relationship between the ulnar styloid process and the DCBUN and to confirm the DCBUN's change in location with different forearm positions. METHODS: We examined 9 fresh frozen cadaveric limbs to establish the course of this nerve. The DCBUN was dissected and traced around the ulnar border of the wrist. The distance from the tip of the ulnar styloid process to the origin of the DCBUN was measured. The distances from the ulnar styloid process to the DCBUN were measured in supination, pronation, and in a neutral position of the forearm. RESULTS: The DCBUN originated on average 4.92 cm proximal to the ulnar styloid process. In all cases, the DCBUN crossed the ulnar distal to ulnar styloid process and it moved more closely to the ulnar styloid process with a forearm position change from supination to pronation. CONCLUSIONS: We recommend making a skin incision on the ulnar side around the styloid process with the forearm in supination or neutral position was another method to avoid injury of DCBUN.

Which Is Better for Arthroscopic Tenodesis of the Long Head of the Biceps: Soft Tissue or Bony Interference Fixation?

PURPOSE: To compare the outcome between arthroscopic soft tissue tenodesis (STT) at the rotator interval and bony interference fixation tenodesis (BIFT) at the distal bicipital groove for the long head of the biceps (LHB). METHODS: Twenty-five shoulders that underwent arthroscopic STT of the LHB were compared with 28 shoulders that underwent arthroscopic BIFT using a 5.5-mm Bio-Tenodesis screw (Arthrex, Naples, FL). American Shoulder and Elbow Surgeons scores, Constant score, and elbow flexion strength index (EFSI) were checked preoperatively, postoperative 1 year and 2 years. Ultrasound imaging evaluation took place at 1 year and 2 years postoperatively as well. RESULTS: The overall functional outcomes improved after surgery in both groups. The BIFT group showed a significant increase in EFSI (preop: 0.54, postoperative 2 years: 0.94) compared with that of the STT group (preop: 0.52, postoperative 2 years: 0.74) at postoperative 2 years (P = .006). However, no significant difference was seen in the increase of American Shoulder and Elbow Surgeons scores and Constant scores between the two groups. At postoperative 2 years, ultrasound showed seven empty grooves in the STT group, but only two empty grooves in the BIFT group (P = .046). CONCLUSIONS: Arthroscopic BIFT for the LHB showed better improvement in EFSI than arthroscopic STT. In addition, the STT group showed a higher failure rate than the BIFT group. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Torsional malalignment, how much significant in the trochanteric fractures?

OBJECTIVES: The rotational alignment is definitely important in the long bones such as tibias and femurs. We also predict the importance of rotational alignment in the trochanteric fractures. So we measured torsional malalignment in trochanteric fracture and anlaysed their risk factors and their clinical significance. METHODS: A total of 109 inpatients who had undergone internal fixation following trochanteric fracture and a postoperative pelvic CT scan between 2008 and 2013, with at least one year follow-up, were selected. Factors that affect torsional malalignment, such as age, gender, fracture stability, injured area, operative time, time of surgery after admission, and ASA status, were investigated. Factors that affect the patients' clinical results in malrotation, including ambulation time after surgery, postoperative complication rates, pain assessment of VAS one year postoperatively and Koval score, were also investigated. RESULTS: Of the 109 subjects, torsional malalignment was observed in 28 (25.7%) subjects with a mean torsional malalignment angle of 20.7° (range: -31.2° to 27.1°). Torsional malalignment risk factors were fracture stability (p=0.021) and operative time (p=0.043). In terms of the time to ambulation after surgery, the postoperative complication rates, and the VAS and Koval scores at one year postoperatively, no statistically significant difference was observed between the torsional malalignment patients and the non-deformity patients. CONCLUSIONS: In this study, 25.7% of the patients who had undergone internal fixation following trochanteric fracture experienced torsional malalignment. Major factors of the torsional malalignment were an unstable fracture and the consequent delay in the operative time. But the torsional malalignment was deemed to have no effect on clinical results.

Incidence and mortality after proximal humerus fractures over 50 years of age in South Korea: national claim data from 2008 to 2012.

BACKGROUND: There has been lack of epidemiology of proximal humerus fracture using nationwide database in Asia. The purpose of this study was to investigate the incidence of proximal humerus fracture and its mortality following proximal humerus fracture in Korean over 50 years of age. METHODS: The Korean National Health Insurance data were evaluated to determine the incidence and mortality of proximal humerus fracture aged 50 years or older from 2008 through 2012. RESULTS: Proximal humerus fracture increased by 40.5% over 5 year of study. The incidence of fracture increased from 104.7/100,000 in 2008 to 124.7/100,000 in 2012 in women and from 45.3/100,000 in 2008 to 52.0/100,000 in 2012 in men, respectively. One year mortality rate after proximal humerus fracture was 8.0% in 2008 and 7.0% in 2012. One year mortality rate were 10.8% for men and 7.0% for women in 2008 and 8.5% for men and 6.4% for women in 2012. CONCLUSIONS: Our study showed that the proximal humerus fracture in elderly was recently increasing and associated with high mortality in Korea. Considering proximal humerus fracture was associated with an increased risk of associated fractures and an increased mortality risk, public health strategy to prevent the proximal humerus fracture in elderly will be mandatory.

Facet joint degeneration of the cervical spine: a computed tomographic analysis of 320 patients.

STUDY DESIGN: Retrospective study. OBJECTIVE: To determine the frequency of facet arthrosis according to age, sex, and cervical level. In addition, we propose and evaluate a new grading system for cervical facet degeneration. SUMMARY OF BACKGROUND DATA: Cervical facets can play an important role in symptomatology. However, there is only one computed tomographic grading system for cervical facet joints. METHODS: From January 2003 to January 2012, 1944 patients underwent computed tomography of the cervical spine in our institution. We randomly selected 40 males and 40 females from each of the following age groups: 40 to 49, 50 to 59, 60 to 69, and 70 to 79, such that we had a total of 320 patients. We then graded the degree of arthrosis of the facet joints from C2 to C7 on the axial, sagittal, or coronal images according to 4 grades. These categories were: grade I, normal; grade II, degenerative changes including joint space narrowing, cyst formation, small osteophytes without joint hypertrophy seen; grade III, facet joint hypertrophy from large osteophytes without fusion; and grade IV, bony fusion of the facet joint. The intra- and interobserver reliabilities for the grading system were calculated using reliability statistics by intraclass correlation. RESULTS: Facet arthrosis is common with older patients and at C2-C3, C3-C4, and C4-C5. Facet arthrosis was more common on the left side and in males. Greater than grade III facet joint arthrosis was common in patients older than 60 and at C2-C3, C3-C4, and C4-C5. The reliability statistics by intraclass correlation for the grading system was 0.878 for the intraobserver reliability and 0.869 for the interobserver reliability. CONCLUSION: It seems that upper cervical levels are more likely to degenerate and to have more advanced degrees of degeneration than the lower cervical levels. As expected, age correlates with worsening degeneration. The proposed computed tomographic grading system for cervical facet arthrosis seemed to be reliable.

Surgical correction for supination loss following malunited radial fractures.

We evaluated fourteen patients who had restricted supination as a major impairment related with a malunited radius fracture. All patients underwent an opening wedge corrective osteotomy, bone grafting, and volar plate fixation. Clinical results were assessed based on range of motion, visual analogue scale for pain, grip power, and a Modified Mayo Wrist Score. The mean supination increased from 24 degrees preoperatively to 71 degrees postoperatively (p < 0.01). Dorsiflexion range, grip power and pain score improved significantly after the operation. The mean value for the Modified Mayo Wrist score improved from 58.6 points to 83.9 points (p < 0.01). Radiological measurements showed that the degree of dorsal angulation decreased from a mean of 9.0 degrees to -2.5 degrees after the corrective osteotomy. This study demonstrated that a malunited radius fracture with dorsal angulation, even if the latter appears mild, can induce functional impairment due to limited range of supination. Supination can be restored by an appropriately performed corrective osteotomy.

Dynamic function of coracoclavicular ligament at different shoulder abduction angles: a study using a 3-dimensional finite element model.

PURPOSE: The aim of this study was to determine the acromioclavicular (AC) motion and change in length and tension of the coracoclavicular ligament during different positions of shoulder abduction using a 3-dimensional finite element model based on computed tomography images from normal human shoulders. METHODS: The right shoulders of 10 living subjects were scanned with a high-resolution computed tomography scanner at 0°, 60°, 120°, and 180° of shoulder abduction. Several modeling programs were used to simulate AC motion. Finite element models of the conoid and trapezoid ligaments were constructed based on each footprint. The tension and length changes of each ligament during shoulder abduction were assessed. RESULTS: The distal clavicle exhibited internal rotation with respect to the medial acromion at 0°, 60°, 120°, and full abduction (3.2° ± 2.9°, 23.2° ± 10.8°, 20.6° ± 3.7°, and 37.1° ± 3.4°, respectively). With horizontal motion, the clavicle translated posteriorly at 60° of abduction (4.4 ± 3.4 mm) and then translated anteriorly at 120° and full abduction (0.4 ± 1.6 mm and 1.9 ± 0.4 mm, respectively). The lengths of the conoid ligament gradually increased at 60° to 180° of shoulder abduction whereas those of the trapezoid ligament remained relatively consistent at 60° to 120° of abduction compared with 0° of abduction. CONCLUSIONS: The distal clavicle had a wide range of motion during shoulder abduction, which did not support the concept of synchronous motion with the scapula. The conoid and trapezoid ligaments functioned reciprocally during shoulder abduction. With increasing shoulder abduction, the length of the conoid ligament gradually increased; meanwhile, the trapezoid ligament was relatively consistent and then lax at full abduction. In particular, the conoid ligament may act as a key restraint to prevent excessive retraction of the scapula during shoulder abduction. CLINICAL RELEVANCE: The data in this study have the potential to suggest that conoid and trapezoid ligaments should be reconstructed separately, and rigid AC fixation in patients with AC separation is not recommended based on the findings of this study.

Symptomatic residual instability with grade II acromioclavicular injury.

PURPOSE: Our objective was to evaluate the effectiveness of arthroscopic distal clavicle resection in cases presenting with pain and subtle instability after neglected grade II acromioclavicular (AC) joint dislocation. METHODS: From February 1998 to May 2006, 17 patients with symptomatic AC instability following chronic grade II AC joint injury were studied. Sixteen patients were male and one female, with a mean age of 48 years. An all-arthroscopic procedure comprising disk removal and distal clavicle resection was performed in all cases. All patients were reviewed clinically, preoperatively and at final follow-up (mean 38 months) using the pain score on a visual analog scale and the Constant score. Strength was measured using an Isobex digital strength analyzer. Patient's personal satisfaction after the procedure was documented as excellent, good or poor. Postoperative AC joint radiographs were routinely obtained in all patients to measure the amount of clavicle resection. RESULTS: Two patients underwent additional reconstructive surgery for disabling pain and dysfunction even after the arthroscopic resection procedure. The remaining 15 patients were analyzed. The pain scores improved significantly (p = 0.03). The mean pain score was 5.8 (range 5-9) before treatment and 1.6 (range 0-3) at follow-up. The Constant scores had improved significantly at the final follow-up (p = 0.001). The median Constant score increased from 46 (range 36-69) preoperatively to 71 (range 48-84) postoperatively. Strength had improved at the last follow-up. Eleven patients were satisfied and six were not satisfied with this procedure at the final follow-up. CONCLUSIONS: Arthroscopic distal clavicle resection statistically improved the pain score, Constant score and strength for grade II AC injury with subtle distal clavicle instability. However, six patients (33.5 %) were not satisfied subjectively. This procedure seemed to be a reasonable initial treatment option with lower morbidity.