Dissemination of Total hip Arthroplasty through the direct anterior approach has, depending upon one's experience and perspective, benefitted from or been plagued by aggressive marketing. Although first developed over 60 years ago it was all but unknown until the past decade. This study exams one community surgeon's experience and thus sheds light on whether the ATHA is a viable operation for all orthopaedic surgeons. 332 hips having a THA through the direct anterior approach were prospectively studied. Side and sex distribution were approximately equal; primary OA was by far the most common diagnosis. 4 hips were converted from a previous operation for fracture. No hips were excluded; all hips were replaced through the direct anterior approach. All hips had the same HA coated, cementless triple-taper stem; a variety of cups were used. 92% of the bearings were ceramic on poly including 22% “dual mobility” design; 88% of the heads were 28 or 32 mm. A special orthopaedic table and intraoperative c-arm were used universally. Charnley Merle D'Aubigne, Harris, and WOMAC scores were obtained before surgery and annually thereafter. Anti-embolic prophylaxis was with intraop bilateral thigh high sequential pumps, early mobilization and aspirin for most. Those patients deemed at risk received lovenox, and those already on Coumadin continued – with bridging lovenox.Introduction
Methods
All patients ultimately benefited from the procedure. The average improvement in knee Society combined knee and function scores was over eighty-five points. The more functional patients experienced the most improvement.
This series is entirely unselected: no patients were excluded because of size or body habitus. One third of the patients had a Body Mass Index greater than 30 (obese); the maximum BMI was 45.6. One third had type C bone and nearly one tenth were category 3 anesthetic risks. Average age was 72 (range 39 to 90). A naive definition of “minimally invasive” is met: the average incision length was 9.5 centimeters (range 6.5 to 13).
There have been three complications requiring readmission: 1 dislocation, 1 unstable acetabulum, and 1 superficial wound breakdown. There has been a total of 3 dislocations-all within 4 days of surgery, none recurrent. One DVT has been detected.
Clinical experience of the ICLH method of resurfacing the hip now spans 10 years. The first 36 arthroplasties, performed between 1972 and 1974, have been previously reported. This review covers in detail 204 such arthroplasties performed between 1975 and 1979 using a standard operative technique and prosthesis; these hips were consecutive and entirely unselected. Follow-up averaged 3.2 years (range two to six years). Successful hips are comparable to hips successfully replaced with stemmed prostheses. The rates of perioperative complications and failure due to infection, ectopic ossification, fracture of the femoral neck, and dislocation are favourably comparable to rates reported for stemmed total hip arthroplasties. The rate of aseptic loosening (17 per cent) greatly exceeded that found for stemmed total hip arthroplasties. Errors of patient selection, operative technique and prosthetic design have been identified. It is concluded that, although resurfacing arthroplasty of the hip may be an appealing procedure with theoretical advantages in certain instances, patient selection is essential, operative technique is demanding and changes in the design of the prosthesis are required. The procedure is still in evolution and therefore it should not yet be generally employed.
The occurrence of a radiolucent line at the interface of bone and cement in total joint prostheses is a frequently observed, although little understood, phenomenon. Because of an operative technique utilised in instances of bone loss, we have, within a single implant mass used in each of a series of 18 total knee replacements, been able to observe two separate interfaces, one between bone and cement and the other between bone and cobalt chrome. The average period of observation was 32 months. All of the knees except one demonstrated a lucency at the bone-cement interface; only one of the knees had a similar lucency at the bone-CoCr interface. One of the knees was studied histologically. In the light of the universal observation of macrophages at bone-cement interfaces and the recent finding that osteoclasts are derived from macrophages, these observations are significant in relation to the aetiology of bone-cement lucencies.