Constrained acetabular inserts provide a solution for both complex primary and revision hip arthroplasty, but there have been ongoing concerns for high risk of failure and their longevity. The Stryker® Trident acetabular insert is pre-assembled with its constrained ring. We believe this to be the largest series of constrained acetabular inserts with a minimum of 5 year follow-up. We retrospectively reviewed all Stryker® Trident ‘All-Poly’ constrained acetabular inserts cemented into bone in our unit between 2008 and 2016. We collated demographic details and reviewed all patients’ radiographs and clinical notes. Indications for surgery, latest Oxford Hip Scores (OHS) and clinical and radiographic complications were identified. 117 consecutive Stryker® Trident ‘All-Poly’ constrained inserts were cemented into bone in 115 patients during the study period with a mean age of 80 (47–97). Most common indications for surgery were recurrent dislocation (47), complex primary arthroplasty (23), revision arthroplasty (19) and failed hemiarthroplasty (12). 41 patients required revision of the acetabular component only. Follow-up was a minimum of 5 years (mean 8.6, range 5–13). There were three 30-day mortalities and six 1-year mortalities. The mean latest OHS was 37 (24–45). Four cups failed in three patients, one at the cement-bone interface, two at the cement-prosthesis interface and one at the bipolar interface. These were treated conservatively in three patient and with excision arthroplasty in one patient. There were four peri-prosthetic fractures, one Vancouver C distal femur fracture treated conservatively and three Vancouver B1 fractures, two treated conservatively and one treated with open reduction internal fixation. There was breakage of one constrained ring with no adverse effects and one superficial wound infection requiring oral antibiotics only. This series demonstrated that despite the elderly and complex nature of these patients’ clinical situations, constrained acetabular inserts offer a useful and pragmatic solution, with relatively low complications, including in our series a cup failure rate of 3% and peri-prosthetic fracture rate of 3%.
We review the results of the Gamma nail fixation to elucidate its effectiveness in the treatment of peritro-chanteric and subtrochanteric fractures of the neck of femur. We report the result of 718 cases of Gamma nail fixation in all such cases presenting at our institution since 1988. 573 cases of peritrochanteric and 145 cases of sub-trochanteric fractures were treated by means of standard and long Gamma nail. Age groups of the patients are from 33 to 99 years. No distal locking screw was used in cases of standard nails. All grades of surgeons were involved. Full weight bearing was allowed on the first post operative day. Cases were followed up for one year. No intraoperative iatrogenic fracture was encountered. Minimal post operative pain was experienced and mobility was regained early. All fractures healed satisfactorily except the following: 51 cases developed coxa vera deformity; 37 cases of undisplaced fractures of base of greater trochanter were noticed at 6 weeks follow up - all healed spontaneously; 1 case of external rotational deformity occurred in a long nail where no distal locking screw was used. 2 cases of deep infection were treated successfully by removal of nail and antibiotic treatment; 4 cases of fracture at the level of the distal end of the prosthesis, presented at 6 weeks to 2 year period following a subsequent trauma, were treated with exchange of device with long nail. Upward penetration of hip screw 22. No case of metal failure observed. Gamma nail provides a stable fixation in both simple and complex fractures of proximal femur with a much less invasive tehcnique which allows minimal disturbance of fracture haematoma, less incidence of wound infection and less amount of postoperative pain. Early mobility is regained with immediate and unrestricted weight bearing. Biomechanically also Gamma nail produces a better means of osteosynthesis.
