Distal Radius Hemiarthroplasty.

INTRODUCTION: Due to a higher risk for implant loosening, particularly of the distal component, patients with physically demanding lifestyles are infrequently considered for total wrist arthroplasty (TWA). A distal radius hemiarthroplasty may obviate the need for the strict restrictions recommended for patients treated by TWA, thus providing another surgical option for active patients with severe wrist arthritis, especially those with articular degeneration of the lunate facet of the radius, capitate head, or combination of both, who are not typically candidates for traditional motion-preserving procedures. MATERIALS AND METHODS: Eight fresh-frozen cadaver limbs (age range, 43-82 years) with no history of rheumatoid arthritis or upper extremity trauma were used. Radiodense markers were inserted in the radius and hand. Posteroanterior (PA) fluoroscopic images with the wrist in neutral, radial deviation, and ulnar deviation, and lateral images with the wrist in neutral, flexion, and extension were obtained for each specimen before implantation, after distal radius hemiarthroplasty, and after combined hemiarthroplasty and PRC. RESULTS: On the PA images, the capitate remained within 1.42 and 2.21 mm of its native radial-ulnar position following hemiarthroplasty and hemiarthroplasty with PRC, respectively. Lateral images showed the capitate remained within 1.06 mm of its native dorsal-volar position following hemiarthroplasty and within 4.69 mm following hemiarthroplasty with PRC. Following hemiarthroplasty, capitate alignment changed 2.33 and 2.59 mm compared with its native longitudinal alignment on PA and lateral films, respectively. These changes did not reach statistical significance. As expected, significant shortening in longitudinal alignment was seen on both PA and lateral films for hemiarthroplasty with PRC. CONCLUSION: A distal radius implant hemiarthroplasty with or without a PRC provides good static alignment of the wrist in a cadaver model and thus supports the concept as potential treatment alternatives for advanced wrist arthritis; however, combined hemiarthroplasty with a PRC has more clinical relevance because it avoids the risk of proximal carpal row instability and eliminates the commonly arthritic radioscaphoid joint.

Early complications of volar plating of distal radius fractures and their relationship to surgeon experience.

BACKGROUND: Fractures of the distal radius are among the most common fractures in adults. Recently, there has been a trend towards open reduction and internal fixation of these fractures through a volar approach. The purpose of this study was to assess the early complications of volar locking plate fixation of distal radius fractures with an emphasis on defining the relationship between surgeon experience and incidence of complications. MATERIALS AND METHODS: Following IRB approval, we conducted a retrospective chart review of the initial 96 distal radius fractures (92 patients) treated by open reduction and internal fixation of distal radius fracture using a volar locked plate. Our outcome measurements were incidence of postoperative complications and radiographic loss of reduction. RESULTS: Twenty-two complications occurred in 21 patients. Of these, five complications (5%) required surgical treatment or hospitalization. Seventeen complications (18%) required no surgical intervention or hospitalization. Transient nerve dysfunction was the most common complication, accounting for 12 of 22 complications. The first 30 patients experienced significantly more complications than those treated later in the series (p = 0.03). There was a trend towards increased incidence of complications in cases where more than 10 days elapsed between injury and surgery or where supplementary Kirschner wire fixation was used. There was no correlation between patient age, sex, severity of fracture, or presence of ulnar styloid fracture and the development of complications or loss of reduction. DISCUSSION: The incidence of complications decreased significantly with increased surgeon experience, suggesting that many of these early complications are avoidable.

Comparison of the native ulnar head and a partial ulnar head resurfacing implant.

PURPOSE: To assess the match in size and shape between the native ulnar head and a partial ulnar head implant in cadaver specimens. METHODS: Ten fresh-frozen cadaver arms (6 male, 4 female, age range 79-91 years) with no history of previous distal radioulnar joint surgery were used. Radiographic measurements before and after implantation were used to compare ulnar head articular height, width, offset, and ulnar variance. Head diameter was measured using photographs of the resected ulnar heads. RESULTS: The partial ulnar head implant consistently reproduced the natural anatomic size and shape for all variables except ulnar head height and ulnar variance. Head height was greater with the implant, but the additional height extended proximally into the distal radioulnar joint synovial recess, which is unlikely to have adverse affects. Ulnar variance match was technique dependent, with a tendency to place the implant in more neutral variance when positive variance was present before surgery. CONCLUSIONS: Our study demonstrated that a partial ulnar head implant, which replaces the articular surfaces, can closely re-create the ulnar head anatomy. By virtue of restoring the anatomy without an extensive dissection, the clinical results should be expected to at least match the functional results of total head replacement, reduce the rehabilitation, and possibly reduce the risk of joint instability.

Early outcome of spherical ceramic trapezial-metacarpal arthroplasty.

PURPOSE: A retrospective review of 50 ceramic, spherical implants for the treatment of trapezial-metacarpal osteoarthritis in 49 patients assessed clinical and radiographic outcome. METHODS: Thirty-five patients returned for a clinical examination and completed an outcome survey at a mean follow-up of 3 years. A radiographic review was available for all 50 implants with a mean follow-up of 3 years. Average patient age at surgery was 59 years (35 women and 15 men). Twenty-five patients were retired and 24 were regularly employed preoperatively. RESULTS: Overall satisfaction was between "very satisfied" and "satisfied" for 32 patients, and none were dissatisfied. Twenty-nine patients rated both frequency and severity of pain as "less than before surgery" or "much less than before surgery." Average rating for thumb and hand strength was the "same as before surgery." Thumb pinch strength averaged 40 N (91% that of the opposite thumb). Postoperative thumb opposition was Kapandji stage 8 or better in 34 of 50 thumbs and stage 6 or better in patients who had an interphalangeal joint or metacarpophalangeal joint fusion. All 24 employed patients returned to work, but 2 required substantial modifications of pinch and grasp movements. Implant subsidence occurred in 47 of 50 thumbs, ranging from 1 to 13 mm. Trapezium fractures occurred in 15 thumbs. Eleven additional thumbs showed erosions and cystic changes within the trapezium or metacarpal. There was no evidence of arthritis developing in surrounding joints. In addition to adverse radiographic changes, there were 10 complications in 10 patients, including implant subluxation in 7 patients. CONCLUSIONS: Although most patients were satisfied with their function and pain relief, adverse radiographic findings were nearly universal. Implant subsidence, especially into the trapezium, was often severe, with some resulting in a trapezium fracture. Based on the radiographic outcome at this medium-term follow-up, we no longer use this implant. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.