Application of the Endomodel rotating hinge knee prosthesis for knee osteoarthritis.

One hundred thirty-six knees were treated with the Endomodel rotating hinge knee prosthesis as primary total knee arthroplasty (TKA). The indications for surgery included osteoarthritis (110 knees), rheumatoid arthritis (18 knees), and osteonecrosis (8 knees). Patients were divided into four study groups according to follow-up duration. Group A was followed up from 10 to 15 years, group B from 8 to 10 years, group C from 5 to 8 years, and group D from 2 to 5 years. The Hospital for Special Surgery knee score, as well as each parameter individually, showed statistically significant improvement in all groups postoperatively. A total of 88.23% were rated as excellent, 3.67% as good, and 8.08% as fair. The results suggest that the Endomodel rotating hinge prosthesis can be considered a good alternative for primary TKA in cases of serious axial deformity and collateral ligament deficiency and in rheumatoid arthritis patients.

Diagnosis and arthroscopic treatment of primary synovial chondromatosis of the shoulder.

Primary synovial chondromatosis of the shoulder is a rare condition. We present the case of a 24-year-old man with a 6-month history of right shoulder pain and decreased range of motion. Computed tomography and magnetic resonance imaging findings led us to the diagnosis of synovial chondromatosis of the shoulder. Arthroscopy revealed loose bodies in the glenohumeral joint, the biceps tendon sheath, and the subscapularis recess. Active intrasynovial proliferation of the axillary pouch was noted. All loose bodies were removed arthroscopically, and partial synovectomy was performed. Histologic examination confirmed the diagnosis of primary synovial chondromatosis. We recommend arthroscopic treatment for synovial chondromatosis of the shoulder because of low morbidity and early functional return.

Intra-articular ganglia of the knee joint associated with the anterior cruciate ligament: a report of 4 cases in 3 patients.

Intra-articular ganglia are rare and mostly incidental findings on magnetic resonance imaging (MRI) and arthroscopy. We present 4 cases of intra-articular ganglion cysts associated with the anterior cruciate ligament (ACL) in 3 patients. The most commonly occurring symptoms were pain aggravated after stressing activities and limited knee range of motion. In 1 patient, ganglion cysts appeared in both knees with a time difference of 1 year. An MRI revealed typical signs of ganglion cysts in the substance of the ACL. Arthroscopy was performed for further evaluation and treatment. Histologic examination of the tissue removed revealed the presence of features consistent with ganglion cysts. Therefore, in the case of chronic knee discomfort with nonspecific clinical signs and symptoms and without a clear cause, an intra-articular ganglion cyst should be considered as causing pathology. An MRI is the most sensitive and specific method for diagnosis. However, the relatively slow progression of symptoms may delay the patient's decision to seek medical attention. Delayed diagnosis makes arthroscopic total resection of the ganglion technically demanding or not possible at all, and extensive debridement of the ACL may be required.

Microsurgical dissection of the carpal tunnel with respect to neurovascular structures at risk during endoscopic carpal tunnel release.

PURPOSE: The goal of this descriptive study was to investigate the anatomy of the carpal tunnel with respect to the related neurovascular structures, because a detailed knowledge of the complex anatomy of this region is essential to perform endoscopic carpal tunnel release. METHODS: Sixteen fresh-frozen cadaveric hands were used for the study. Dissection of the palmar aspect of the hand was performed by use of magnifying loupes, an operative microscope, and microsurgical instruments. All anatomic components were photographed, and dimensions were recorded by use of a micrometer. The distance from the radial aspect of the os pisiformis and the proximal and distal portals to the main structures that may be injured was measured. Topography of the transverse ligament and possible adhesions to the tendons and median nerve were also recorded. RESULTS: The mean distance from the radial aspect of the os pisiformis to the radial border of Guyon's canal and the ulnar edge of the palmaris longus tendon was 10.3 mm (range, 9 to 12 mm) and 16.1 mm (range, 12 to 22 mm), respectively. The mean distance from the distal portal to the superficial palmar arch and the ulnar artery was 10.4 mm (range, 5 to 15 mm) and 7.6 mm (range, 4.5 to 9 mm), respectively. The mean distance from the distal edge of the transverse ligament to the thenar branch of the median nerve was 2.7 mm (range, 0 to 4.1 mm). The mean length of the transverse ligament was 31 mm (range, 25 to 34.5 mm). In 14 hands we also identified the palmaris longus tendon. In 11 hands we found adhesions between the transverse ligament and the sheath of the flexor tendons. CONCLUSIONS: The palmaris longus can be used as a guide for the placement of the proximal portal. Staying at the ulnar side of the palmaris longus keeps the superficial palmar branch of the median nerve at a safe distance from the instruments. The "fat drop sign" is also a useful guide for the placement of the distal margin of the transverse carpal ligament, keeping the distal portal away from the superficial palmar arch. Synovial adhesions can usually cover the inferior surface of the transverse ligament, and they need to be removed for clear endoscopic identification of the transverse fibers before the ligament is cut. CLINICAL RELEVANCE: Detailed knowledge of the complex anatomy of the carpal tunnel is essential to perform endoscopic carpal tunnel release.