Biomedical subjects

Andrew Haskell

Publications and source records attributed to Andrew Haskell.

7 recordsLinked to original sources

PubMed2004

Ankle arthroplasty with preoperative coronal plane deformity: short-term results.

The treatment of coronal plane deformity during total ankle arthroplasty is understood poorly. This study tests the hypotheses that preoperative coronal plane malalignment and incongruence of the ankle can be corrected and maintained for 2 years with total ankle replacement, and that factors can be identified that place ankles at risk of having progressive edge-loading develop. Of 86 consecutive patients who had total ankle replacement, 35 had preoperative coronal plane alignment > or =10 degrees. Lateral ligament reconstruction was done in seven patients and superficial deltoid release was done in four patients at the time of ankle replacement. Ankles with talar and tibial deformities improved talar and tibial alignment toward a neutral weightbearing axis postoperatively. Ankles with only a talar deformity improved the talar alignment toward a neutral weightbearing axis postoperatively. No changes in alignment were shown during the subsequent 2 years. Postoperative ankle articulations were congruent. Patients with preoperative incongruent joints are 10 times more likely to have progressive edge-loading develop than patients with congruent joints. Surgeons must be attentive to coronal plane alignment during and after ankle replacement. Longer followup is needed to assess the longevity of the correction and the impact of minor malalignment on implant wear.

Ankle Joint↗

PubMed2004

Perioperative complication rate of total ankle replacement is reduced by surgeon experience.

BACKGROUND: Recent studies suggest the perioperative complication rate of total ankle arthroplasty decreases as a surgeon becomes familiar with the procedure. This study tests the hypothesis that the number of perioperative adverse events will decrease as surgeon experience with total ankle replacement increases. METHODS: Ten surgeons completed retrospective chart and radiographic reviews of their first 10 cases as well as 10 subsequent cases of the Scandinavian Total Ankle Replacement (STAR). Not all surgeons completed 10 cases within the allotted time periods, and two patients were excluded for less than 3-month follow-up, resulting in 187 cases for review. The surgeons performed an average of 12.8 (range, 0-61) STARs between these two time periods. Cases were divided into Early Group if they were among the first five STARs a surgeon performed and Late Group if they were after the first five. RESULTS: The average patient age was 60.4 +/- 12.8 years. The etiology of arthrosis included 96 (51%) of 187 posttraumatic, 49 (26%) idiopathic, and 33 (18%) rheumatoid. Patients in Early Group had a 3.1 times greater chance of having a perioperative adverse event (95% CI 1.6-6.1, p <.001), and a 3.2 times greater chance of having a perioperative wound problem (95% CI 1.5-6.8, p =.002) than patients in Late Group. Patients in Early Group took 1 week longer to heal their wounds than patients in Late Group (4.5 vs. 3.5 weeks, p =.046). CONCLUSIONS: This study shows a decrease in the perioperative adverse event rate commensurate with surgeon experience with STAR. In contrast to other reports, this study was unable to show a decrease in the number of perioperative fractures with increasing surgeon experience. This information is important for planning how best to train surgeons new to total ankle replacement and for patient counseling regarding the potential risks of the procedure.

Ankle Injuries↗

PubMed2004

Subtalar joint arthrodesis using a single lag screw.

BACKGROUND: This study tested the hypotheses that fusing the subtalar joint with a single lag screw from the posteroinferior calcaneus to the anterior talar neck is an effective technique and that factors affecting the time to fusion can be identified. METHODS: Between October, 1995, and July, 2002, the senior author (RAM) performed 101 isolated subtalar arthrodeses using a technique of single lag-screw fixation from posteroinferior to anterosuperior across the posterior facet of the subtalar joint combined with the application of an autograft taken from the floor of the sinus tarsi and anterior process. The average patient age was 52 (range 17 to 82) years. There were 52 women (53 arthrodeses) and 48 men (48 arthrodeses). Eight of 101 (8%) arthrodeses were revisions. The indications included posttraumatic arthritis (45), posterior tibial tendon dysfunction (18), failed prior ankle joint fusion (14), idiopathic disorders (12), hindfoot coalition (7), rheumatoid arthritis (3), and Charcot-Marie-Tooth disease (2). Fifteen of 101 patients (15%) smoked an average of 0.9 +/- 0.5 pack of cigarettes per day. RESULTS: Two of 101 joints did not fuse, resulting in an overall fusion rate of 98%. The average time to fusion was 12.3 +/- 3.4 weeks. The presence of a prior ankle fusion significantly prolonged the time to fusion of the subtalar joint (11.9 +/- 2.3 vs. 14.9 +/- 7.0, p = .003). Other factors, including smoking, revision surgery, patient age, and patient sex, did not affect time to fusion. The fixation screw was removed in 13 of 101 (13%) joints at an average of 8.8 +/- 0.5 months. CONCLUSIONS: Using a single 7.0-mm lag screw across the posterior facet of the subtalar joint results in fusion of the subtalar joint in 98% of patients. A prior ankle arthrodesis delays the time to fusion of the subtalar joint by 3 weeks. This is a simple and reliable technique for achieving fusion of the subtalar joint.

Adolescent↗

PubMed2003

Metachronous multicentric giant cell tumor: a case report and literature review.

Metachronous multicentric giant cell tumors of bone are rare. The case of a 47-year-old woman who had a giant cell tumor of the ilium develop 24 years after resection of a giant cell tumor of the proximal tibia is reported. The initial and current surgical approaches for this patient are described. A literature review is presented to show that this patient had the longest disease-free interval documented for a patient with metachronous multicentric giant cell tumors.

Adult↗

PubMed2002

The University of California at San Francisco international orthopaedic elective.

International volunteerism helps remedy global inequities in orthopaedic care and provides relief for increasing professional disillusionment experienced by many orthopaedic surgeons in the United States. From 1992 to 1998, 41% of residents from the Department of Orthopaedic Surgery at the University of California, San Francisco volunteered overseas. Approximately one half of those have continued volunteering internationally after residency, including many who led later trips with residents. Based on the success of these trips, the University of California, San Francisco Department of Orthopaedic Surgery established a 1-month elective rotation in Umtata, South Africa in conjunction with Orthopaedics Overseas. Seventy-six percent of residents have chosen this opportunity since the program's inception in 1998. The University of California, San Francisco experience suggests that early exposure to international volunteerism during residency promotes continued participation in volunteer activities after graduation. By providing residents with the opportunity to volunteer overseas, the University of California, San Francisco hopes to enhance resident education, foster a lifelong spirit of volunteerism, and serve as a model for other orthopaedic training programs.

Humans↗

PubMed2002

Biomechanical testing of bioabsorbable cannulated screws for slipped capital femoral epiphysis fixation.

This study compared cannulated 4.5-mm bioabsorbable screws made of self-reinforced poly-levolactic acid to cannulated 4.5-mm steel and titanium screws for resistance to shear stress and ability to generate compression in a polyurethane foam model of slipped capital femoral epiphysis fixation. The maximum shear stress resisted by the three screw types was similar (self-reinforced poly-levolactic acid 371 +/- 146 MPa, steel 442 +/- 43 MPa, and titanium 470 +/- 91 MPa). The maximum compression generated by both the self-reinforced poly-levolactic acid screw (68.5 +/- 3.3 N) and the steel screw (63.3 +/- 5.9 N) was greater than that for the titanium screw (3 +/- 1.4 N, P <.05). These data suggest cannulated self-reinforced poly-levolactic acid screws can be used in the treatment of slipped capital femoral epiphysis because of their sufficient biomechanical strength.

Absorbable Implants↗

PubMedDate not supplied

Fixation of osteoporotic distal fibula fractures: A biomechanical comparison of locking versus conventional plates.

The increased use of locking plates to treat difficult fracture scenarios has been advocated in patients that have reduced bone mineral density. One of these difficult fracture patterns, fixation of the distal fragment of a distal fibula fracture, may depend on unicortical and cancellous bony purchase. This study investigated the construct stiffness afforded by using locking and conventional plating schema in a cadaveric model. Overall, the data indicate that a locking plate construct with two distal unicortical screws was mechanically equivalent to standard plating with 3 distal screws. In addition, fixation with the standard plates was dependent on bone mineral density (BMD) whereas the locking plate fixation was independent of BMD. The clinical implication of this study is that locking plates may be advantageous in patients with the most severe osteoporosis.

Aged↗