A systematic approach to predicting the risk of unicompartmental knee arthroplasty revision.

OBJECTIVE: Unicompartmental knee arthroplasty (UKA) revision is usually due to the degenerative degree of knee articular osteochondral tissue in the untreated compartment. However, it is difficult to simulate the biomechanical behavior on this tissue accurately. This study presents and validates a reliable system to predict which osteoarthritis (OA) patients may suffer revision as a result of biomechanical reasons after having UKA. DESIGN: We collected all revision cases available (n = 11) and randomly selected 67 UKA cases to keep the revision prevalence of almost 14%. All these 78 cases have been followed at least 2 years. An elastic model is designed to characterize the biomechanical behavior of the articular osteochondral tissue for each patient. After calculated the force on the tissue, finite element method (FEM) is applied to calculating the strain of each tissue node. Kernel Ridge Regression (KRR) method is used to model the relationship between the strain information and the risk of revision. Therefore, the risk of UKA revision can be predicted by this integrated model. RESULTS: Leave-one-out (LOO) cross-validation (CV) is implemented to assess the prediction accuracy. As a result, the mean prediction accuracy is 93.58% for all these cases, demonstrating the high value of this model as a decision-making assistant for surgical plaining of knee OA. CONCLUSIONS: The results of this study demonstrated that this integrated model can predict the risk of UKA revision with theoretically high accuracy. It combines bio-mechanical and statistical learning approach to create a surgical planning tool which may support clinical decision in the future.

Arthroscopic excision of the radial head: Clinical outcome in 12 patients with post-traumatic arthritis after fracture of the radial head or rheumatoid arthritis.

PURPOSE: We performed arthroscopic radial head excision in a series of patients with either post-traumatic arthritis after a radial head fracture or rheumatoid arthritis of the elbow as an expanded indication for elbow arthroscopy. The purpose of the study was to critically examine the results of arthroscopic chondroplasty of the radial head to determine the safety and effectiveness of the procedure. TYPE OF STUDY: Outcome study and retrospective analysis. METHODS: From 1990 to 1997, arthroscopic radial head resection was performed in 12 patients with either post-traumatic arthritis (n = 10, Mason type II or III) or with rheumatoid arthritis (n = 2). Functional outcome and radiographs were analyzed after a mean follow-up period of 39 months (range, 12 to 97 months). Elbow arthroscopy was performed using a standardized technique. The anterior three quarters of the radial head and 2 to 3 mm of the radial neck were resected with the abrader in the anterolateral portal and the arthroscope in the proximal medial portal. For resection of the posterior portion of the radial head, the abrader may be transferred to the mediolateral portal. This permits resection of the remnants of the radial head posteriorly and also at the proximal radioulnar joint. RESULTS: Preoperatively, patients lacked 23 degrees (range, 5 degrees to 40 degrees ) of extension of the elbow on average. Mean flexion was 111 degrees (range, 60 degrees to 145 degrees ). Patients had unrestricted pronation (limitation of 5 degrees in 2 patients). Two patients had a lack of supination of 15 degrees and 30 degrees. Mean follow up was 39 months (range, 12 to 97 months). Postoperatively, patients lacked 9 degrees (range, 0 degrees to 20 degrees ) of extension of the elbow on average. Mean flexion was 136 degrees (range, 90 degrees to 150 degrees ). No patient had subjective or objective evidence of instability of the elbow. All patients except one reported significant improvement in pain relief and complete relief of mechanical symptoms. CONCLUSIONS: This technically demanding surgical procedure should be reserved for situations of persistent, restricted range of motion and chronic pain. Arthroscopic radial head resection combined with arthroscopic synovectomy relieves elbow stiffness. The surgeon is able to deal with the intrinsic joint pathology, as well as with accompanying symptoms such as synovitis, capsular contracture, or loose bodies.

The role of hip arthroscopy in the evaluation of avascular necrosis.

This prospective study evaluated the correlation between plain radiographs, magnetic resonance imaging (MRI), and diagnostic arthroscopy in the staging of avascular necrosis of the femoral head. Fifty-two hips in 46 patients were prospectively staged using radiographic and MRI staging systems. Patients subsequently underwent hip arthroscopy to visualize the articular surface prior to considering salvage of the femoral head and debride delaminated osteochondral fragments. Weighted Kappa analysis revealed only moderate correlation between MRI and plain radiographs (K=.11), MRI and arthroscopy (K=.21), and plain radiographs and arthroscopy (K=.19). Six (46%) of 13 patients with a radiographically apparent subchondral fracture demonstrated collapse of the articular surface at arthroscopy. Four (24%) of 17 hips with >2 mm of collapse of the femoral head on plain radiographs demonstrated fragmentation of the osteochondral surface of the femoral head at arthroscopy. In 5 patients with flattening of the femoral head, 3 patients had delamination of both the femoral and acetabular surfaces. In regard to labral pathology, 5 of 22 post-collapse hips also had large bucket handle tears of the labrum. Arthroscopy of the hip revealed osteochondral degeneration that was not detected by plain radiographs or MRI in 36% of post-collapse femoral heads.

Preiser's disease: arthroscopic treatment of avascular necrosis of the scaphoid.

We report the case of a 50-year-old female patient with Preiser's disease (avascular necrosis of the scaphoid) who, after a 2-year history of wrist pain, underwent arthroscopic debridement of the necrotic scaphoid using a standard technique. Osteoarthritic changes of the articular cartilage, partial rupture of the scapholunate ligament, local synovitis, and loose fragments were documented. The patient reported significant improvement in pain relief and complete relief of mechanical symptoms at 31-month follow-up examination. Radiographs demonstrated no progression of collapse of the scaphoid or acceleration of degenerative changes in the wrist. Arthroscopy in Preiser's disease allows direct visualization and assessment of the exact pathology of the radiocarpal and midcarpal joint and the scaphoid cartilage. Arthroscopic debridement of the necrotic scaphoid increased wrist functional range of motion, provided excellent pain relief, and improved health-related quality of life.

Hip arthroscopy in staging avascular necrosis of the femoral head.

The purposes of this study were to evaluate how accurately current imaging modalities predict the quality of the articular surface in avascular necrosis (AVN) of the femoral head and to provide arthroscopic correlation to current staging modalities. An arthroscopic classification system, derived from the work of Marcus et al, was used to prospectively stage the articular surface in 23 hips with AVN using plain radiographs, magnetic resonance imaging (MRI), and arthroscopy. There was little correlation between all three diagnostic modalities. These findings were not statistically significant. Patients with stage IV disease had the widest variation in the appearance of the articular surface. This study shows poor correlation in the staging of AVN using current imaging techniques. Magnetic resonance imaging has been shown to be inadequate at assessing the articular cartilage. Therefore, either arthroscopy or direct visualization is required for accurate evaluation and staging, especially in stage IV disease.

Arthroscopic resection of the radial head.

The authors describe arthroscopic radial head resection in patients with post-traumatic arthritis after fractures of the radial head or in patients with rheumatoid arthritis of the elbow joint, as an expanded indication for elbow arthroscopy. Arthroscopic radial head resection allows the surgeon to deal with the intrinsic joint pathology, as well as with accompanying symptoms such as synovitis, capsular contracture, or loose bodies. The portals used are the proximal medial, anterolateral, and the midlateral portal. The anterior three quarters of the radial head and 2 to 3 mm of the radial neck are resected with the stone-cutting abrader in the anterolateral portal and the arthroscope in the proximal medial portal. For resection of the posterior portion of the radial head, the abrader may be transferred to the midlateral portal. This permits resection of the remnants of the radial head posteriorly and also at the proximal radioulnar joint. Arthroscopic treatment allows the patient to begin and maintain an aggressive postoperative physical therapy program immediately after surgery, thus decreasing the risk of anterior scarring and reoccurring contracture of the capsule of the elbow joint.

Arthroscopic debridement for the treatment of Kienbock's disease.

The treatment results of seven patients (age range, 37 to 74 years, male:female ratio, 1:6) with Kienbock's disease (Lichtman stage IIIA-IIIB) who underwent arthroscopic debridement of the necrotic lunate bone and degenerative intrinsic ligaments were studied retrospectively. Osteoarthritic changes of the articular cartilage were documented in all cases. Partial (n = 2) and complete (n = 5) ruptures of the lunotriquetral and scapholunate ligaments, local synovitis (n = 5), and loose fragments (n = 6) occurred most commonly in the radiocarpal joint. All patients were available for an average of 19 months of follow-up (range, 6 to 42 months), physical examination, and radiographic evaluation. All patients reported significant improvement in pain relief and complete relief of mechanical symptoms. Radiographs showed progression of the disease in three cases; two of these were followed-up for more than 2 years. Arthroscopy in Kienbock's disease allows direct visualization and assessment of the exact pathology of the radiocarpal and midcarpal joint and the lunate cartilage. Arthroscopic debridement of the necrotic lunate increased wrist functional range of motion, provided excellent pain relief, and improved health-related quality of life in all patients.

The arthroscopic management of osteochondritis dissecans of the adolescent elbow.

The management of avascular necrosis of the capitellum of the adolescent elbow continues to be a dilemma. This article is a critical retrospective analysis of 12 pediatric patients (mean age at surgery 14.5 years) who underwent arthroscopic debridement alone followed by early range of motion. Follow-up at a mean of 3.2 years (range, 2.0 to 5.7 years) indicated that the average flexion contracture improved from 23 degrees preoperatively to 10 degrees postoperatively. All patients had remodeling of the capitellum by plain radiographs; however, five patients had associated enlargement of the radial head. Eleven patients had minimal mechanical symptoms after the procedure and were highly satisfied. One patient had substantial enlargement of the radial head with continued loss of supination and mechanical symptoms requiring radial head resection 2 years after the index procedure. Five patients had a triangular avulsion fragment present off the lateral capsule. A statistically significant worse subjective outcome was associated with the presence of this fragment (P < .005). There were no complications.

Significance of cold intolerance in upper extremity disorders.

After upper extremity injury, pain on exposure to cold (cold sensitivity) is a significant problem. This cross-sectional observational study (1) assesses the incidence and prevalence of cold intolerance, (2) evaluates the relationship between functional status and degree of cold intolerance, and (3) correlates health-related quality of life (HRQL) with symptoms of cold intolerance. Patients in a tertiary care center completed questionnaires to document (1) cold sensitivity, (2) upper extremity pain, symptoms, and function, and (3) HRQL. Cold sensitivity was found to be associated with more functional limitations, greater pain, and reduced HRQL. As the severity of cold intolerance increased, functional limitations and pain increased and HRQL decreased. Cold intolerance has a profound effect on HRQL.

The arthroscopic treatment of avascular necrosis of the proximal pole following scaphoid nonunion.

The authors describe a technique of treating scaphoid nonunions with associated avascular necrosis consisting of arthroscopic resection of the distal pole of the scaphoid combined with radial styloidectomy. The results at 2-year follow-up showed all three patients to have complete relief of their mechanical pain and improvement in their range of motion as well as high satisfaction with the procedure. Modified Mayo Wrist Scores were a mean preoperatively of 60 and postoperatively of 88. Postoperative radiographs showed no increase in the scapholunate gap. However, the capitolunate angle increased from a mean of 3 degrees to 13 degrees . There was no progression of degenerative changes noted. The advantages of this technique include (1) minimal morbidity, (2) relief of mechanical pain, and (3) improved range of motion with no early degenerative changes. The rate and severity of degenerative change following this procedure remain unknown.

The role of operative arthroscopy for the diagnosis and treatment of lesions about the distal ulna.

Operative arthroscopy of the wrist compliments the physical examination and radiographic imaging to improve diagnosis and treatment of lesions about the distal ulna. This article reviews the relevant anatomy, biomechanics, and classification of acute and degenerative lesions of the triangular fibrocartilage complex (TFCC). Minimally invasive diagnostic and management techniques for TFCC tears are described in detail.

Translaminar lumbar epidural endoscopy: technique and clinical results.

To provide baseline outcome data for a new lumbar microinvasive diskectomy done with standard arthroscopic instrumentation, we retrospectively reviewed the cases of 190 patients. All patients were assessed by a modified MacNab outcome classification with a minimum of a 2-year follow-up. All complications of this procedure were reported as well. No previous outcome data are available for this procedure, since it has been done primarily at one center, by the same surgeon, using his previously reported techniques. Results were good or excellent in 175 patients and fair or poor in 15. Complications were not severe and were easily remedied. This success rate is comparable to rates reported for other minimally invasive operations on the lumbar spine. This new technique of minimally invasive lumbar spine surgery provides minimal morbidity and a long-term outcome comparable to that of other standard procedures. The added benefits of using standard arthroscopic instrumentation are discussed.

Cartilage injuries: a review of 31,516 knee arthroscopies.

Although articular cartilage injuries of the knee are common, injured cartilage has a limited ability to heal. Recent data suggest that articular cartilage grafting may provide treatment for these injuries. To define the patient population that might benefit from cartilage grafting, 31,516 knee arthroscopies were reviewed. Between June 1991 and October 1995, 53,569 hyaline cartilage lesions were documented in 19,827 patients. The majority were articular cartilage lesions; grade III lesions of the patella were the most common. Grade IV lesions were predominantly located on the medial femoral condyle. Patients under 40 years of age with grade IV lesions accounted for 5% of all arthroscopies; 74% of these patients had a single chondral lesions (4% of the arthroscopies). No associated ligamentous or meniscal pathology was found in 36.6% of these patients.

Pigmented villonodular synovitis and synovial chondromatosis arthroscopically diagnosed and treated in the same elbow.

This case is a report of arthroscopically diagnosed synovial chondromatosis and pigmented villonodular synovitis in the same elbow. A literature review found no prior reports of an association of these entities. Arthroscopy appears to be effective in the management of pigmented villonodular synovitis and synovial chondromatosis in the elbow.

Anterior interosseus nerve injury following elbow arthroscopy.

Elbow arthroscopy is becoming an increasingly invaluable tool for both evaluation of and treatment of a variety of interarticular disease processes. Case reports have documented radial and posterior interosseus injuries following anterior capsular release. To date, this is the first report of an anterior interosseus nerve injury following arthroscopic surgery of the elbow. Arthroscopic surgery offers unparalleled visualization of the multiple articulations and facets of the elbow. It has been reported as useful for removal of loose bodies, synovectomy, release of arthrofibrosis, and the treatment of osteochondritis dessicans. However, the technique does require thorough knowledge of neurovascular structures about the elbow as well as appreciation of the protective layers including the capsule, brachialis, and brachioradialis muscles. This report documents direct injury to the anterior interosseus branch of the median nerve during an elbow debridement and synovectomy in a 65-year-old patient with rheumatoid arthritis.

New Tuohy needle technique for triangular fibrocartilage complex repair: preliminary studies.

The treatment of injuries to the triangular fibrocartilage complex (TFCC) has evolved from closed casting through open excision to arthroscopic repair. The authors present the preliminary results of arthroscopic repair of peripheral (Palmer type IB) TFCC tears using a Tuohy needle. Results in 17 patients treated with this technique were obtained retrospectively through chart review and telephone interview. Average age of the patients was 33 years (range, 16 to 54 years). Conservative treatment averaged 9 months (range, 2 to 26 months). The repairs were performed with one or two horizontal mattress sutures of 2-0 polydioxanone. Follow-up ranged from 4 to 13 months (average, 8 months). Sixteen patients were satisfied or very satisfied with the result; 1 was not satisfied. No complications occurred. We believe this Tuohy needle technique is practical and cost-effective for the arthroscopic management of peripheral TFCC tears.

Arthroscopy of the wrist in athletes.

Athletes are prone to a variety of pathologic conditions of the wrist. Wrist arthroscopy has become an effective tool in the diagnosis and treatment of athletes with wrist problems. Because it is minimally invasive, wrist arthroscopy often allows early return to training and competition. This article discusses the causes of wrist problems in athletes, their classification, the portals, and the intra-articular anatomy in the context of arthroscopic intervention.