Andrew A. Freiberg

Nonoperative treatment of trigger fingers and thumbs.

This article reports our experience with the management of 93 consecutive patients with 108 trigger digits initially treated by triamcinolone acetonide injections into the flexor tendon sheath. It appears that two distinct clinical types of trigger digits exist--nodular and diffuse. Ninety-three percent (63/68) success was obtained in the nodular type compared with 48% (10/33) in the diffuse type (p less than 0.05). We conclude that the patients with the nodular type should be offered a simple cortisone injection. Those patients seen initially with the diffuse type should probably be offered surgical decompression.

Large diameter femoral heads on highly cross-linked polyethylene: minimum 3-year results.

Contemporary highly cross-linked polyethylenes have become the most widely used alternative bearing surfaces in total hip replacement and may be paired with large diameter femoral heads (> 32 mm) in patients considered to be at high risk for dislocation. We report on a prospective series of 42 patients (45 hips) who had total hip replacement using large diameter cobalt-chrome femoral heads articulating with a highly cross linked polyethylene after a minimum of 3 years followup (mean 3.3 years). At final followup, the final patient cohort showed excellent clinical results with no radiographic failures or episodes of loosening. There was no evidence of pelvic or femoral osteolysis. One patient sustained a dislocation due to a grossly malpositioned acetabular component necessitating early isolated acetabular revision. The average yearly steady state wear rate was −0.06 ± 0.41 mm/year. The results of our short-term prospective series indicated total hip replacement with large femoral heads articulating with a highly cross linked polyethylene showed excellent wear characteristics and clinical results and could be considered in patients at increased risk for dislocation.Level of Evidence: Therapeutic studies, level IV (case series). See Guidelines for Authors for a complete description of levels of evidence.

Effector Function of Resting T Cells: Activation of Synovial Fibroblasts

Synovial tissue in rheumatoid arthritis is characterized by infiltration with large numbers of T lymphocytes and APCs as well as hyperplasia of synovial fibroblasts. Current understanding of the pathogenesis of RA includes the concept that synovial fibroblasts, which are essential to cartilage and bone destruction, are regulated by cytokines derived primarily from monocyte-macrophage cells. Recently it has been found that synovial fibroblasts can also function as accessory cells for T cell activation by superantigens and other stimuli. We have now found that highly purified resting T cells, even in the absence of T cell mitogens, induce activation of synovial fibroblasts when cocultured for 6–24 h. Such activation was evident by induction or augmentation of mRNA for stromelysin, IL-6, and IL-8, gene products important in joint inflammation and joint destruction. Furthermore, increased production of IL-6 and IL-8 was quantitated by intracellular cytokine staining and flow cytometry. This technique, previously used for analysis of T cell function, was readily adaptable for assays of synovial fibroblasts. Resting T cells also induced synovial fibroblasts to produce PGE2, indicating activation of expression of the cyclooxygenase 2 gene. Synergy was observed between the effects of IL-17, a cytokine derived from stimulated T cells that activates fibroblasts, and resting T lymphocytes. Various subsets of T cells, CD4+, CD8+, CD45RO+, and CD45RA+ all had comparable ability to induce synovial fibroblast activation. These results establish an Ag-independent effector function for resting T cells that is likely to be important in inflammatory compartments in which large numbers of T lymphocytes and fibroblasts can come into direct contact with each other.

In Vivo Patellar Tracking: Clinical Motions and Patellofemoral Indices

Patellar tracking during in vivo weightbearing knee function is not well understood. This study investigated patellar tracking of eight subjects during a full range of weightbearing flexion using magnetic resonance imaging and dual orthogonal fluoroscopy. The data were reported using a clinical description based on patellar and femoral joint coordinate systems and using patellar indices based on geometrical features of the femur and patella. The mean patellar shift was within 3 mm over the entire range of flexion. The patella tilted laterally from 0° to 75°, and then tilted medially beyond 75° of flexion. The mean tilt was within 6°. Similarly, the mean patellar rotation was small at early flexion, and the mean total excursion of patellar rotation was about 8°. The patellofemoral indices showed that the mean sulcus angle and congruence angle varied within 8° over the entire flexion range. The mean lateral patellar displacement was within 6 mm. A consistent decrease in lateral patellar tilt and an increase in lateral patellofemoral angle were observed with knee flexion. In conclusion, patellar motion is relatively small with respect to the femur during in vivo weightbearing knee flexion. These data may provide baseline knowledge for understanding normal patellar tracking.

Infected total knee arthroplasty treated with arthrodesis using a modular nail.

Failed treatment of infected total knee replacement presents few attractive surgical options. Knee arthrodesis is challenging surgically and can be complicated by nonunion, malunion, or recurrent infection. Recently, a modular titanium intramedullary nail has been used in an attempt to reduce the incidence of nonunion and the rate of complications. In the present study, a review of the results of knee arthrodesis after infected total knee arthroplasty in 21 patients at three large academic institutions was performed. All patients were followed up for a mean of 2.4 years (range, 2-7.5 years). The mean age of the patients was 64 years. The mean number of previous operations was four (range, 2-9 operations). A solid arthrodesis was achieved without additional surgical treatment in 20 of 21 patients (95%). The mean time to fusion was 6.3 months. The one patient who suffered a nonunion achieved fusion after a subsequent bone grafting procedure. Based on the present study, intramedullary arthrodesis with a coupled titanium nail, is a reliable, effective method of achieving fusion after infection of a total knee arthroplasty. This procedure resulted in a high rate of fusion and a lower rate of complications when compared with traditional methods of arthrodesis.

Aneurysmal bone cysts in young children

We reviewed seven young children (< or = 10 years) with aneurysmal bone cysts. There were four girls and three boys. Six had involvement of the long bones and one had involvement of the clavicle. The average age was 5.5 years (range 2.9-10.6 years). Initial treatment was curettage and bone grafting. There were recurrences in five of the seven children (71%). This represented 100% of children with radiographically aggressive or active lesions. The recurrences appeared rapidly, at an average of 8 months from the first procedure. The mitotic index of the initial lesion did not correlate with that of the recurrent lesion. Surgical management of the recurrences must be handled individually, but repeat curettage and grafting is only recommended when surgical resection is not possible. This high rate of recurrence in radiographically aggressive or active aneurysmal bone cysts in young children should be considered when planning treatment, and in the preoperative counseling of parents.

Minimum 6-year followup of highly cross-linked polyethylene in THA.

To reduce wear rates and particulate debris, highly cross-linked polyethylene has been in use in total hip arthroplasty for 8 years. We designed this followup study to primarily determine the total penetration rate of the femoral head and the steady-state wear rate of cross-linked polyethylene in patients undergoing primary total hip arthroplasty. We retrospectively reviewed data from 182 patients (200 hips) with a minimum 6-year followup (mean, 6.9 years; range, 6-8 years) and an average age of 60.2 years at surgery. The average Harris hip score, University of California-Los Angeles activity score, and WOMAC score were 91.1, 6.3, and 11.3, respectively. Radiographic evaluation showed no evidence of loosening or osteolytic lesions around the cup or stem. No revisions were performed for polyethylene wear or liner fracture. The average steady-state wear rate was −0.002 ± 0.01 mm per year and −0.026 ± 0.13 mm per year for 28-mm and 32-mm head sizes, respectively. We observed no correlation between the total wear rate and femoral head size, brand of polyethylene, age, gender, primary diagnosis, mode of fixation, surgical approach, University of California-Los Angeles activity score, Harris hip score, or WOMAC. Highly cross-linked polyethylene liners are associated with excellent midterm clinical, radiographic, and wear results in this group of patients.Level of Evidence: Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Three-dimensional tibiofemoral articular contact kinematics of a cruciate-retaining total knee arthroplasty

BACKGROUND Accurate knowledge of the location of tibiofemoral articular contact following total knee arthroplasty is important in order to understand polyethylene wear and the mechanisms of component failure. The present study was performed to determine the three-dimensional tibiofemoral articular contact patterns of a posterior cruciate ligament-retaining total knee replacement during in vivo weight-bearing flexion. METHODS Nine osteoarthritic patients who were managed with a single design of a posterior cruciate ligament-retaining total knee implant were investigated with the use of an innovative dual orthogonal fluoroscopic imaging system. The position of the components during in vivo weight-bearing flexion was measured from full extension to maximum flexion in 15 degrees intervals. Tibiofemoral articular contact was determined by the overlap of the tibiofemoral articular surfaces. The centroid of the surface intersection was used to report the point of contact location. The average tibiofemoral contact points on both the medial and lateral tibial component surfaces were reported as a function of flexion. RESULTS The average maximum weight-bearing flexion angle was 113.3 degrees +/- 13.1 degrees (range, 96 degrees to 138 degrees ). In the anteroposterior direction, the contact location was relatively constant in the medial compartment and moved posteriorly by 5.6 mm in the lateral compartment as the knee flexed from full extension to 90 degrees of flexion. The range of the contact location in the mediolateral direction was 3.7 mm in the medial compartment and 4.8 mm in the lateral compartment. For both compartments, posterior translation of the contact point was significant from 90 degrees to maximum flexion, but the contact point at maximum flexion was not observed to reach the posterior edge of the polyethylene tibial insert articular surface. CONCLUSIONS While the minimum anteroposterior translation of the contact point on the medial side might be interpreted as a medial pivot rotation during knee flexion, the contact point did move in the mediolateral direction with flexion. Beyond 90 degrees , both medial and lateral contact points were shown to move posteriorly but stopped before reaching the posterior edge of the polyethylene tibial insert articular surface. It seemed that the current component design did not allow the femoral condyle to roll off the polyethylene edge at high degrees of flexion because of the geometry at the posterior lip.

Malignant melanoma of the foot and ankle.

The records of sixty patients who had a malignant melanoma of the foot or ankle were reviewed retrospectively to determine the clinical features, prognostic factors, and distinguishing characteristics. Fifty-seven patients were white and three were black. There were forty-two women and eighteen men (a female-to-male ratio of 2.3 to 1). The mean age at the time of presentation was fifty-seven years (range, twenty-two to eighty-three years). The most common site of involvement was the plantar aspect of the foot. The mean duration of follow-up was forty-five months (range, three to 144 months). Kaplan-Meier life-table analysis revealed an over-all five-year survival rate of 63 per cent and an over-all ten-year survival rate of 51 per cent. The mean duration of survival for the patients who had a plantar or subungual lesion was significantly shorter than that for the patients who had a lesion at another site on the dorsal aspect of the foot or on the ankle (forty-seven compared with seventy-two months) (p = 0.02). The mean depth of the lesion, according to the criteria of Breslow, was 3.03 millimeters, and the mean level, according to the classification of Clark et al., was IV. According to the classification of the American Joint Commission on Cancer, forty-three patients had stage-I or II (local) disease, thirteen had stage-III disease (nodal or in-transit disease, defined as cutaneous or subcutaneous metastases more than two centimeters from the primary tumor but not beyond the regional lymph nodes), and four had stage-IV disease (distant visceral metastases) at the time of presentation. Lesions at plantar and subungual sites were also associated with a higher prevalence of clinical misdiagnosis compared with lesions on the dorsal aspect of the foot or on the ankle (p = 0.02). The misdiagnoses included a benign nevus (one patient), a paronychia (one patient), a pyogenic granuloma (two patients), a plantar wart (three patients), a ganglion cyst (one patient), a blister (two patients), and a traumatic lesion (five patients).(ABSTRACT TRUNCATED AT 250 WORDS)

Use of patellar allograft to reconstruct a patellar tendon-deficient knee after total joint arthroplasty

A catastrophic complication after total knee arthroplasty (TKA) is rupture of the patellar tendon. Several techniques for treatment have been described, including cast immobilization with or without operative repair, the use of a semitendinosus, fascia lata, or hamstring tendon autogenous graft, the use of a Dacron 4-mm vascular graft (U.S. Catheter and Instrument, Glen Falls, NY), the use of bovine xenograft and even transplantation of an entire allograft extensor mechanism. Treatment results of patellar tendon rupture after TKA can be discouraging. Altered tissue quality secondary to connective tissue diseases, diabetes, rheumatoid arthritis, lupus erythematosus, secondary hyperparathyroidism, or concurrent steroid medications contributes to poor results. Additionally, no one treatment has provided consistent clinical success. Successful treatment of a patient with a ruptured patellar tendon after TKA using the bone-patellar tendon-bone allograft commonly used for anterior cruciate ligament reconstruction is reported.