Maturation process of regenerated tissues after single-stage simultaneous autologous particulated cartilage implantation and open wedge high tibial osteotomy for articular cartilage defects with medial osteoarthritis of bilateral knees: a case report.

BACKGROUND: Open wedge high tibial osteotomy (OWHTO) is an effective treatment option for young and middle-aged active patients with medial unicompartmental knee osteoarthritis (OA). In addition, particulated cartilage implantation has been developed as a simple procedure for cartilage regeneration. Thus, to improve the OWHTO outcomes, a single-stage, simultaneous bilateral knee arthroscopic particulated cartilage implantation with OWHTO was performed. CASE PRESENTATION: A 60-year-old male patient presented with severe bilateral knee pain, with grade 2 varus knee OA of the Kellgren-Lawrence classification. Primary arthroscopic evaluations based on the International Cartilage Repair Society grading system showed grade 3c articular cartilage defects of 1.5 cm in diameter at the center of the bilateral medial femoral condyles. Following bilateral OWHTO, the healthy cartilage tissue was harvested from the lateral wall of the unilateral femoral intercondylar notch and minced with the cartilage processor. Then, subchondral drillings and cartilage fragment implantations into the bilateral defects were performed arthroscopically. One year postsurgery, second-look arthroscopy findings revealed that the defects were filled with cartilage-like tissues. The maturation process of the regenerated tissues was confirmed with T2 mapping magnetic resonance imaging during the 3-year follow-up period. The patient could walk without a cane, and all Knee Injury and Osteoarthritis Outcome Score parameters were improved without any correction loss in 3 years. CONCLUSIONS: This is the first report to evaluate the maturation process of the implanted particulated cartilage tissue with T2 mapping magnetic resonance imaging for 3 years. The effect of chondral resurfacing procedure with OWHTO remains unclear; however, the implantation of arthroscopic particulated cartilage fragments is a single-stage and less-invasive procedure. This treatment could regenerate cartilage-like tissue in the present case. Therefore, this additional procedure could potentially improve the long-term outcomes of OWHTO.

The Presence and the Location of an Ulnar Styloid Fracture Associated With Distal Radius Fracture Predict the Presence of Triangular Fibrocartilage Complex 1B Injury.

PURPOSE: To investigate the correlation between ulnar styloid fracture (USF) associated with distal radius fracture (DRF) and triangular fibrocartilage complex (TFCC) injuries and to elucidate whether the presence or location of an USF in a patient with DRF predicts the presence of traumatic TFCC injuries. METHODS: From 2005 to 2018, an arthroscopic evaluation was performed to detect TFCC injuries associated with DRF. The presence and location of USFs were evaluated using computed tomography. TFCC injuries were classified in accordance with Palmer's classification. All wrists were divided into group A (DRF without USF) and group B (DRF with USF). The incidence of TFCC injuries in the 2 groups was compared. group B was then divided into 2 subgroups in accordance with the USF location: the tip or middle fracture subgroup and the base fracture subgroup. Data were analyzed with significance set at P < .05. RESULTS: One hundred thirty-eight patients were enrolled in this study. Group A included 42 wrists in 42 patients, whereas group B included 96 wrists in 96 patients. There were significant differences between the 2 groups regarding the incidence of traumatic TFCC injuries (P = .036) and TFCC 1B injury (P = .002), although there were no differences between the 2 groups regarding age, sex, injured side, direction of displacement, and type of DRF. Within group B, the tip and middle fracture subgroup included 37 wrists in 37 patients, whereas the base fracture group included 59 wrists in 59 patients; a significant difference was observed between the two subgroups regarding the incidences of TFCC 1B injuries (P = .044). CONCLUSIONS: The presence of USF associated with DRF predicted the presence of frequently occurring traumatic TFCC injury and TFCC 1B injury. Moreover, the location of USFs was a predictive factor for TFCC 1B injury in adults with DRF. On the other hand, traumatic TFCC injury had occurred in adults with DRF, regardless of the presence of USF. LEVEL OF EVIDENCE: Level IV, Case series.

Benefits of bone graft augmentation to arthroscopic Bankart repair for recurrent anterior shoulder instability with glenoid bone loss.

PURPOSE: Glenoid bone loss contributes to recurrent instability after arthroscopic Bankart repair alone. With significant glenoid bone loss, better results have been reported after arthroscopic Bankart repair with glenoid arc reconstruction. However, no reports compare augmentation using bone graft with non-augmentation for glenoid bone loss. The purpose of this study was to assess clinical results of an arthroscopic Bankart repair with or without arthroscopic bone graft augmentation. It was hypothesized that such bone graft augmentation would restore shoulder stability, and lead to excellent outcomes. METHODS: Of 552 patients treated for anterior glenohumeral instability with arthroscopic Bankart repair, 68 met this study's inclusion criteria of glenoid bone loss over 20% and follow-up of at least 2 years. Patients were divided into 2 groups based on whether with bone graft augmentation for glenoid bone loss [Group A: n = 35, median age; 21 years (range 13-72 years)], or not (Group B: n = 33, median age; 21 years (range 13-50 years)]. For grafting, either autologous iliac bone or artificial bone made of hydroxyapatite was used. Rowe score, recurrence rate, and return to sport were used to assess the results. RESULTS: Mean Rowe score was 95.0 (SD 10.6) in Group A and 69.7 (SD 27.2) in Group B (p < 0.05). The recurrence rate was 2.9% (1/36) in Group A and 48.5% (16/33) in Group B (p < 0.05). Regarding contact/collision athletes, 24 were contained in Group A and 22 in Group B. Of the patients with recurrence in Group B, 13 (59.1%) were contact/collision athletes. Finally, 50% of the contact/collision sports athletes for both groups returned to their sports at the same as pre-injury level. Of the 11 patients who returned to the same level of contact/collision sports in Group B, seven returned with residual instability. Nine athletes in Group A and 3 in Group B quit their sports for personal or social reasons. CONCLUSIONS: Bone graft augmentation was beneficial when used with Arthroscopic Bankart repair for recurrent anterior shoulder instability with glenoid bone loss. Especially, for recurrent anterior shoulder instability with glenoid bone loss in contact/collision sports athletes, bone graft augmentation should be strongly considered as beneficial. LEVEL OF EVIDENCE: Level IV.

Morphological evaluation of the scapula by three-dimensional computed tomography to elucidate shoulder joint function.

INTRODUCTION: There are many variations of scapula morphology. Evaluation of scapula morphology is necessary to elucidate shoulder joint movement. We aimed to analyze the bone morphology of various parts constituting the scapula to identify certain conserved features among them. MATERIALS AND METHODS: Thirty-one healthy individuals were the subjects. We created a scapular three-dimensional (3D) model using computed tomography (CT). X and Y axes were set on a glenoid surface. We measured the approximate plane of the upper and lower scapular bodies and scapular spine and the central axis of the coracoid and acromion. The anatomical position of the scapular spine, upper and lower bodies, coracoid, and acromion was measured. The positional relationship between the upper and lower bodies and scapular spine and the coracoid and acromion was evaluated. The average angle of the upper and lower scapular bodies and the scapular spine with respect to the XZ plane was calculated. The average angle of the coracoid and acromion with the X-axis on the XY plane and Z-axis on the YZ plane was calculated. RESULTS: On the XY plane, approximate planes of the upper and lower part of the body and the scapular spine were significantly correlated to each inclination. On the XY plane, inclinations of the central axes of the coracoid and acromion were significantly correlated. CONCLUSIONS: The findings revealed for the first time the correlation between the inclinations of the scapular body and scapular spine and the inclination angle between the coracoid and acromion.

Effect of physical therapy on early knee osteoarthritis with medial meniscal posterior tear assessed by MRI T2 mapping and 3D-to-2D registration technique: A prospective intervention study.

Objectives: The purpose of this study was to verify that exercise aimed at improving knee kinematics in early-stage knee osteoarthritis (OA) patients with medial meniscus posterior root tears (MMPRTs) reduces knee adduction angle during gait and prevents rapid cartilage degeneration in the medial compartment of the knee.Methods: Subjects were randomly assigned to an adapting alignment exercise (AAE) group, with the goal of improving knee kinematics, and a muscle training and exercise (MTE) group. Before the start of the six-month intervention and following its completion, we performed an analysis of knee kinematics during gait using a 3D-to-2D registration technique and identified the area of cartilage degeneration using MRI T2 mapping.Results: The amount of change between pre- and post-intervention measurements of the maximum angle of adduction was 0.48° (95% CI: -0.14, 1.09) in the MTE group and -0.40° (-0.84, 0.04) in the AAE group (p = .039). The amount of change in the area of cartilage degeneration according to MRI T2 mapping expressed as MTE/AAE group was 7.7 mm2 (-0.4, 15.8)/-2.7 mm2 (-10.8, 5.3) at the posterior knee (p = .043).Conclusion: AAE could be a potential treatment method that improves the natural course of knee OA with MMRPTs.

Posterior tibial slope angle is associated with flexion-type Salter-Harris II and Watson-Jones type IV fractures of the proximal tibia.

PURPOSE: Flexion-type Salter-Harris (SH) II fractures of the proximal tibia, also described as Watson-Jones (WJ) IV fractures, are rare injuries reported among adolescent athletes who are close to skeletal maturity and remain elusive. Due to this classification disagreement, the various treatments range from nonoperative to operative types, and no previous studies have explained the mechanisms of injury or the source of the fracture forces. This retrospective matched case-control study aimed to identify radiological factors that are associated with the fracture forces and to elucidate the mechanisms of these injuries. METHODS: Sixteen flexion-type SH II/WJ IV fractures of the proximal tibia in 12 adolescents (12 males, mean age of 14.6 years) were retrospectively reviewed, and knee alignment on plain radiographs was assessed to compare the radiological outcomes of the operated knees (n = 7), nonoperated knees (n = 9), and uninjured contralateral knees (n = 8). The results were compared to healthy age- and sex-matched control subjects (n = 24 knees). RESULTS: With regard to the radiological outcomes, the posterior tibial slope angle (PTSA) was significantly greater in the nonoperated knees (19.0° ± 1.6°), operated knees (16.8° ± 1.3°), and uninjured knees (13.6° ± 1.3°) than in the healthy knees of the matched control subjects (9.6° ± 0.4°). The anatomical tibiofemoral angle was significantly less in the nonoperated knees (0.7° ± 0.6°) than in the healthy knees of the matched control subjects (3.7° ± 0.4°). CONCLUSIONS: These findings suggest a relationship between an increased PTSA and flexion-type SH II/WJ IV fractures of the proximal tibia, considering the deteriorating effects of an increased PTSA on knee kinematics. Adolescent active athletes with an increased PTSA and partially closed epiphysis of the proximal tibia are at risk for suffering from flexion-type SH II/WJ IV fractures of the proximal tibia until the closure of the proximal tibial epiphysis. LEVEL OF EVIDENCE: Case-control study, Level III.

Closing Radial Wedge Osteotomy for Preiser Disease: Clinical Outcomes.

PURPOSE: To determine clinical outcomes of Preiser disease treated with closing radial wedge osteotomy (CRWO). METHODS: Seven patients with Preiser disease underwent CRWO. Two wrists had stage 2 disease, 3 had stage 3, 2 had stage 4 (Herbert-Lanzetta classification). Magnetic resonance imaging (MRI) showed that 4 wrists had stage 1 and 3 had stage 2 indicating complete and incomplete necrosis, respectively (Kalainov criteria), before surgery. Two wrists had concomitant Kienböck disease. The range of motion (ROM) of the wrists was restricted owing to pain, and median Modified Mayo Wrist Score (MMWS) was 15 points. Patients were followed after surgery with radiography, MRI, and clinical evaluation (ROM, grip strength, MMWS). Radiolunate and scapholunate angles were calculated on lateral radiographs. RESULTS: Although there were no usual postoperative complications (eg, infection, neuropathy, distal radius nonunion), 1 patient had an extensor pollicis longus tendon rupture, and another experienced osteoarthritis with deterioration of the distal radioulnar joint. Final follow-up radiography showed that 2 wrists were stage 3, 5 were stage 5 (Herbert-Lanzetta classification). At 1 year after surgery, T1-weighted MRI showed that 2 of 6 wrists had improved from stage 1 to stage 2 (Kalainov criteria). At the final evaluation, 5 wrists had no pain, and 2 had only mild pain. Compared with the contralateral wrist, the median ROM was 80% in extension, 73% in flexion. Median grip strength was 71%, median MMWS was 75 points, and clinical results were good in 1 patient, fair in 5, and poor in 1. CONCLUSIONS: Although follow-up radiography showed that the disease stage had progressed in 4 of 7 patients, wrist pain alleviation, retention of ROM, and improvement of grip strength were obtained. The CRWO may be an option for reducing wrist pain and retaining ROM of the wrist owing to Preiser disease. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic V.

Suitable reference gene selection for gene expression studies in knee osteoarthritis synovium using quantitative PCR analysis.

Osteoarthritis (OA) is the leading cause of musculoskeletal disability in the elderly. Insights into the biological features of OA are obtained by characterization of the molecular features by gene expression profiling using reverse transcription-quantitative PCR (RT-qPCR). However, it has recently become evident that the use of suitable reference genes is required for appropriate normalization of this technique. Here total RNA was isolated from the synovium of 18 men and 20 women who underwent total knee arthroplasty for knee OA (KOA). We validated the expression stability of 7 candidate housekeeping genes (ACTB, B2M, GAPDH, HPRT1, RPL13A, SDHA, and YWHAZ) in the synovium of KOA with 3 commonly used algorithms (geNorm, NormFinder, and BestKeeper). Additionally, we evaluated expression profiles of the steroid hormone receptor (AR, ESR1, ESR2, GR, MR, and PR) and proinflammatory cytokines (IL1B and IL6) genes in the synovium and their correlations with the risk factors of KOA, using the most and least stable housekeeping genes for comparison. Results showed that HPRT1 was the most stable gene, whereas B2M was the least stable. RT-qPCR analysis revealed sexually dimorphic expression of AR, IL1B, and IL6; intercorrelations between steroid hormone receptor expression levels and female-specific correlations of IL1B expression with ESR1 and PR expression, IL6 expression with ESR1 and GR expression, and body mass index with AR and PR expression; and the choice of the least stable reference gene altered several correlations and statistical significances. In conclusion, HPRT1 was identified as the suitable reference gene for normalization in the OA synovium.

Intramuscular Epithelioid Sarcoma Presenting as Extrinsic Flexor Tightness in the Forearm.

Epithelioid sarcoma is an uncommon soft tissue sarcoma involving predominantly the distal extremities of adolescents and young adults. Its rarity makes it difficult to diagnose accurately and treat properly in the early stages. We discuss the delayed diagnosis of a 37-year-old man who presented with extrinsic flexor tightness of the wrist and fingers. We initially thought that the lesion resulted from inflamed soft tissue of the flexor muscles causing contracture. However, histological examination of a biopsy specimen revealed nodular proliferation of epithelioid and spindle cells, which were immunoreactive to epithelial and nonepithelial markers, respectively, leading to the final diagnosis of epithelioid sarcoma.

Functional outcomes after the Sauvé-Kapandji procedure for distal radio-ulnar post-traumatic instability: a case-control comparison of three different operative methods of stabilization of the ulnar stump.

PURPOSE: This study was performed to elucidate the cause of proximal ulnar stump pain by comparing the clinical results and radiographic changes among three treatment groups involving different Sauvé-Kapandji procedures. METHODS: Thirty-seven patients (38 wrists) with distal radioulnar joint disorders followed up for ≥ six months post-operatively were investigated. Patients were treated by one of three Sauvé-Kapandji procedures. In group A (13 wrists), the original Sauvé-Kapandji procedure was performed. Groups B (13 wrists) and C (12 wrists) involved different modified Sauvé-Kapandji procedures with stabilization of the proximal ulnar stump using the extensor carpi ulnaris tendon. At the final examination, we evaluated wrist pain, proximal ulnar stump pain, the ranges of forearm pronation/supination, grip strength, the grip strength ratio between the affected and unaffected sides, and the clinical evaluation score. Standard posteroanterior and lateral radiographs during rest and during maximal gripping were taken for each patient at the final examination, and radiographic parameters were measured. RESULTS: Although significant differences in the frequency of ulnar stump pain were observed between group A and group B or C, no significant differences in wrist pain or the clinical evaluation score were observed. Moreover, no differences in the radiographic changes were noted among the three procedures. CONCLUSION: These findings suggest that proximal ulnar stump pain may be caused not by radial or dorsal deviation of the proximal ulnar stump but by other dynamic factors.

Bone morphological factors influencing cartilage degeneration in the knee.

OBJECTIVES: Morphological features of the distal femur and proximal tibia associated with cartilage degeneration are unknown. This study aimed to elucidate local anatomical parameters of the knee which correlate with articular cartilage degeneration using MRI T1ρ mapping. METHODS: This study involved 200 subjects with knee pain (mean age, 48.7 years; range, 14-80 years) with no severe osteoarthritic changes on plain X-ray. T1ρ values were measured in the regions of interest on the surface layer of the cartilage on mid-coronal images of the femorotibial joint. Assessment of medial and lateral posterior tibial slope (MTS, LTS) and medial and lateral femoral condylar offset ratio (MFCOR, LFCOR) was performed using sagittal proton density-weighted imaging. Morphological assessment of posterior root and horn of menisci was also performed according to a modified Whole Organ Magnetic Resonance Imaging Score (WORMS) of the knee. RESULTS: Multiple regression analysis revealed that a decrease in MTS was associated with increased T1ρ values in the medial tibia, independent of age, osteoarthritic changes on plain X-ray, femur-tibia angle (FTA), and posterior medial meniscal lesions. CONCLUSIONS: Shallow MTS correlates with cartilage degeneration in symptomatic patients. This parameter could help in understanding the etiology of osteoarthritis in the early stage. Future kinematic studies will be needed to confirm our findings.

Split Fracture of the Posteromedial Tubercle of the Talus: Case Report and Proposed Classification System.

We describe a rare case of a fracture of the medial tubercle of the posterior process of the talus in a 16-year-old male athlete who fell during basketball practice. The patient presented to our orthopedic clinic when pain and swelling had persisted despite 2 weeks of anti-inflammatory medication and rest. Computed tomography and magnetic resonance imaging scans revealed a fracture of the posteromedial tubercle of the talus and a small amount of retained fluid in the joint. Immobilization with a below-the-knee cast and non-weightbearing for 4 weeks, with a gradual return to full activity, was successful. At the 1-year follow-up evaluation, the patient expressed no complaints. Fracture of the posteromedial tubercle of the talus will usually result in a misdiagnosis or delayed diagnosis owing to the insidious onset of symptoms. We believe the present fracture configuration resulted from the vertical compression force that occurred on landing by posterior medial ankle impingement in plantarflexion-supination, modifying the conventional concept of the posteromedial tubercle fracture. We also present a suggested classification with a flowchart diagram.

Influence of the Medial Knee Structures on Valgus and Rotatory Stability in Total Knee Arthroplasty.

BACKGROUND: Precise biomechanical knowledge of individual components of the MCL is critical for proper MCL release during TKA. This study was to define the influences of the deep MCL and the POL on valgus and rotatory stability in TKA using cadaveric knees. METHODS: This study used six fresh-frozen cadaveric knees. All TKA procedures were performed using a cruciate-retaining TKA with a CT-free navigation system. We did a sequential sectioning on each knee, S1; femoral arthroplasty only, S2; medial half tibial resection with spacer, S3; anterior cruciate ligament cut, S4; tibial arthroplasty, S5; release of the dMCL, S6; release of the POL. The navigation system monitored motion after application of 10 N-m valgus loads and 5 N-m internal and external rotation torques to the tibia at 0°, 20°, 30°, 60°, and 90° of knee flexion for each sequence. RESULTS: There were no significant differences in medial gaps. Internal rotation angles significantly increased after S2 at 0°, 20°, and 30°, and after S6 at 90° compared with those after S1. External rotation angles significantly increased after S3 at 0°, S4 at 60°, S5 at 0°, 30° and 90°, and after S6 at 30°, 60° compared with those after S1. CONCLUSION: Significant increases of rotatory instability were seen on release of the dMCL, and then further increased after release of the POL. Surgical approach of retaining the dMCL and POL has a possibility to improve the outcome after primary TKA.

A pilot study comparing the efficacy of radiofrequency and microwave diathermy in combination with intra-articular injection of hyaluronic acid in knee osteoarthritis.

[Purpose] This study aimed to compare the efficacy of radiofrequency diathermy with that of microwave diathermy in combination with intra-articular injection of hyaluronic acid into the knee of patients with osteoarthritis (OA). [Subjects] A total of 17 patients with knee OA were enrolled. The participants were randomly divided into two groups: a radiofrequency diathermy group (RF group, 9 subjects), and a microwave diathermy group (MW group, 8 subjects). [Methods] Subjects received radiofrequency or microwave thermal therapy 3 times at 1-week intervals. Intra-articular injection of hyaluronic acid was administered 10 min before every thermal therapy session. The outcome was evaluated using the Japan Orthopaedic Association (JOA) and the Lequesne Index (LI) at baseline, at weeks 1 (1 week after the first thermal therapy) and 3 (1 week after the last thermal therapy). [Results] The JOA scale increased significantly after three sessions of thermal therapy in the RF group, while no significant increase was observed in the MW group. LI decreased significantly after 3 weeks in the RF group. In the MW group, there was no significant difference in LI between the two time points. [Conclusion] This study revealed that symptom relief in patients with knee OA was greater with radiofrequency diathermy than with microwave diathermy with concurrent use of hyaluronic acid injection, presumably due to the different heating characteristics of the two methods.

Transverse Movement of the Median Nerve in the Carpal Tunnel during Wrist and Finger Motion in Patients with Carpal Tunnel Syndrome.

Carpal tunnel syndrome (CTS) is the most common peripheral compression neuropathy of the upper extremity. Repetitive wrist and finger motion has been suggested as a major factor of pathogenesis of CTS. However, little is known about the pathomechanics of CTS. We aimed to evaluate the movement of the median nerve in the carpal tunnel during wrist and finger motions using transverse ultrasound in 21 patients with CTS (5 men and 16 women with mean age 69.0 years). We examined quantitatively the median nerve location as a coordinate within the carpal tunnel at varied wrist positions with all fingers full extension and flexion respectively in the affected and unaffected sides. We thus found that at all wrist positions during finger motion, the median nerve moved significantly more ulnopalmarly in the affected side compared to the unaffected side (p < 0.05). Especially, at the wrist palmar-flexion position as a provocative test, the nerve moved significantly (p < 0.05) the most ulnopalmarly among all wrist positions in the affected side. The nerve was the most strongly compressed against the transverse carpal ligament by the flexor tendons. Additionally, the displacement amount of the nerve in the dorsal-palmar direction was significantly smaller in the affected side than in the unaffected side. These findings indicate that such a pattern of nerve movement has the potential to distinguish affected from unaffected individuals. This ultrasound information could be useful in better understanding of the pathomechanics of CTS, and in further improvement of diagnosis and treatment for CTS.

The outcome of hemiarthroplasty for proximal humeral fractures is dependent on the status of the rotator cuff.

PURPOSE: The purpose of this study was to evaluate clinical and radiological outcomes of hemiarthroplasty for proximal humerus fractures. METHODS: Thirty-five patients (33 women and two men), average age at the time of surgery of 75.1 (range, 64-92) years, who underwent hemiarthroplasty for proximal humerus fracture or fracture-dislocation of the shoulder were enrolled in this study. The Constant score was used for clinical evaluation of outcomes, and X-rays were performed after a minimum follow-up period of 12 months postoperatively. Parameters for radiological evaluation were as follows: value of acromiohumeral interval (AHI), humeral offset, medial and lateral projection, and the existence of subacromial spur, a radiolucent zone around humeral stem and an osteolytic change of the greater tuberosity. RESULTS: The average follow-up after surgery was 45.8 (range, 13-114) months. The average postoperative Constant score was 76.2 (range, 53-96) points. The mean values of AHI and humeral offset were 8.4 and 28.3 mm, respectively. A subacromial spur was observed in ten patients, and an osteolytic change of the greater tuberosity in seven patients. There was a significant correlation between Constant score and values of AHI or humeral offset. The Constant score in patients with a subacromial spur or radiolucent zone around humeral stem was markedly lower than that in patients without them. CONCLUSIONS: The clinical outcome of hemiarthroplasty was influenced by factors reflecting function and conditions of the rotator cuff. Anatomical reconstruction and bone union of the tuberosities need to ensure clinical success in hemiarthroplasty.

Role of the superior shoulder capsule in passive stability of the glenohumeral joint.

BACKGROUND: The shoulder capsule is the main static stabilizer of the glenohumeral joint. However, few studies specifically address the function of the superior shoulder capsule, which is usually damaged in patients with complete rotator cuff tears. Therefore, the purpose of this study was to determine the biomechanical contribution of the superior shoulder capsule to passive stability of the glenohumeral joint. METHODS: Seven cadaveric shoulders were tested with a custom testing system. Glenohumeral translations, subacromial contact pressure, and glenohumeral external and internal rotations were quantified at 5°, 30°, and 60° of glenohumeral abduction. Data were compared among 3 conditions: (1) intact superior capsule, (2) after detaching the superior capsule from the greater tuberosity (tear model), and (3) after complete removal of the superior capsule from the greater tuberosity to the superior glenoid (defect model). RESULTS: A tear of the superior capsule significantly (P < .05) increased anterior and inferior translations compared with those in the intact capsule. Creation of a superior capsular defect significantly (P < .05) increased glenohumeral translation in all directions, subacromial contact pressure at 30° of glenohumeral abduction, and external and internal rotations compared with those of the intact capsule. CONCLUSION: The superior shoulder capsule plays an important role in passive stability of the glenohumeral joint. A tear in the superior capsule at the greater tuberosity, which may be seen with partial rotator cuff tears, increased anterior and inferior translations. A defect in the superior capsule, seen in massive cuff tears, increased glenohumeral translations in all directions.

Relationship between Severity of Varus Osteoarthritis of the Knee and Contracture of Medial Structures.

BACKGROUND: Knees with severe varus osteoarthritis can develop medial structure contracture. However, there is no report on the relationship between severity of varus deformity and contracture of the medial structure. We aimed to determine the threshold angle that could be corrected in proportion to the width of medial osteophyte removal and to examine correction differences between angles larger and smaller than the threshold angle in total knee arthroplasty. METHODS: This study included 27 varus osteoarthritic knees scheduled for total knee arthroplasty (TKA). A navigation system was used to measure hip-knee-ankle angle (HKA) in all knees at maximum extension and 30˚ and 60˚ flexion, before and after osteophyte removal and with and without external 10 N-m valgus torque loads. Subsequently, resected osteophyte widths were measured. Mean correction angle per 1 mm of osteophyte removal was calculated, and the threshold angle was calculated with the receiver operating characteristic curve. HKA differences were compared against deformities larger and smaller than the threshold angle. RESULTS: Mean osteophyte width was 7.1±2.20 mm. Osteophyte removal produced a mean 3.1° correction, which equaled a 0.4° correction per 1 mm of osteophyte width removal. The varus deformity threshold angle was 9.5°. However, when comparing groups with angles larger and smaller than the threshold angle, there was no significant difference in HKA difference between each step and flexion angle. CONCLUSIONS: The threshold angle for expected correction with medial osteophyte removal was 9.5˚. However, because there were no differences in correction between those with angles larger or smaller than this, medial structure contracture seemed to be unrelated to the severity of deformity.

The Influence of Posterior Cruciate Ligament Resection on Tibiofemoral Joint Gap in Varus Osteoarthritic Knees.

Posterior cruciate ligament (PCL) resection during posterior-stabilized total knee arthroplasty (PS-TKA) has been reported to preferentially increase the tibiofemoral joint gap in flexion compared with extension. However, previous assessments of the joint gaps have been performed after bone resection and medial soft tissue release. Thus, these procedural steps may have the potential to influence soft tissue balance. In native knees, soft tissue laxity is generally greater in the lateral compartment than in the medial compartment both with the knee in extension and in flexion. Some surgeons may retain this natural soft tissue balance with less aggressive medial release during TKA. We performed this study to evaluate the impact of the PCL resection on the extension and flexion gaps in the absence of bone resection or medial soft tissue release. Tibiofemoral joint gaps for 41 patients (10 males and 31 females) in full extension and at 90 degrees of flexion both before and after the resections of both the anterior cruciate ligament (ACL) and PCL were assessed using a ligament tensioner device. The statistical analyze was performed using the Mann-Whitney U test. The results showed that medial gap in extension and flexion were 6.7 ± 1.0 and 7.3 ± 0.9 mm, and lateral gap in extension and flexion were 7.6 ± 1.1 and 8.4 ± 1.6 mm, respectively. Thus, physiological tibiofemoral gaps just after knee arthrotomy were trapezoidal and asymmetric shape with the significantly wider gaps in lateral and flexion, compared with the medial and extension, respectively (p < 0.05). However, the increases of the gaps with the ACL and PCL resections were less than 1 mm under the existence of medial soft tissues. As the medial collateral ligament is the primary restraint for the valgus instability, it was also considered to prevent the increase of the flexion gap although the PCL-which is the secondary restraint for the valgus instability-was resected. This finding is critically important for orthopedic surgeons applying PS-TKA implants, particularly for preserving soft tissues to achieve natural knee kinematics postoperatively.

The influence of patellar dislocation on the femoro-tibial loading during total knee arthroplasty.

PURPOSE: Balancing the gap is essential in total knee arthroplasty (TKA). The purpose of this study was to quantify the influence of patellar position on femoro-tibial joint load in TKA. We hypothesized that resetting of the patella increased medial joint load and decreased lateral joint load. METHODS: Our original tensor system was used during posterior-stabilized (PS) and cruciate-retaining (CR) total knee arthroplasty (TKA) using medial para-patellar approach (MPP) or sub-vastus approach (SV). RESULTS: In PS-TKA, by resetting the patella, the ratios between medial and lateral compartments were not changed in both extension and flexion position using MPP and were significantly changed in flexion position using SV. In CR-TKA, by resetting the patella, the load of the lateral component decreased and the ratios between medial and lateral compartments were changed significantly in both extension and flexion position using SV. CONCLUSION: It is important to be aware that, when performing CR-KA, the load of the lateral compartment will decrease by resetting the patella using SV.