[Resection hip arthroplasty--mid- and long-term results].

PURPOSE OF THE STUDY
The study deals with resection hip arthroplasty, which is currently one of the principal orthopedic surgery procedures.The aim of the study was to evaluate the mid- and long-term results of resection arthroplasty carried out for different indications and to ascertain effects of the extent of proximal femur resection on the functional outcome.


MATERIAL
In the period from 1979 to 2000, we carried out 159 resection hip arthroplasties for septic and aseptic loosening of total hip arthroplasty (THA), septic arthritis or osteomyelitis. Of these only the patients who underwent no THA implantation or reimplantation within 2 years of the operation were evaluated. We assessed 102 patients (71 women and 31 men) with 105 resection arthroplasties for the following indications: 14 cases of aseptic loosening of the THA, 72 cases of septic loosening and 19 cases of hip inflammation. The average follow-up was 70.8 months (range, 26 months to 20 years). The average age of the patients at the time of surgery was 62.5 years (29 to 86 years).


METHODS
We recorded the patient's subjective evaluation of the surgery outcome, shortening of the extremity, and the range of hip motion. Harris hip scores were used to assess the functional outcome. We also evaluated, and statistically analysed, the extent of resection of the proximal femur on X-ray images and its effect on the eventual shortening of the extremity; this was done on the basis of the Grauer classification system.


RESULTS
The average Harris hip score was 63.2 points (range, 47 to 88). None of the joints achieved excellent outcomes; 8.5 % were good, 22 % were satisfactory and 73 % were poor. On pain evaluation, 35 % of the patients were completely free from pain, 18 % reported mild pain not interfering with daily activities, 27 % experienced moderate pain responding to common analgetics and 11 % had severe pain necessary to be treated with strong analgetics. Persistent rest pain not responding to analgetics was in 9 % of the patients. The average shortening of the extremity for the whole group was 4.1 cm (range, 3.5- 7 cm): the average values for shortening in type I, type II and type II resections were 3.25 cm (3-5 cm), 4.1 cm (3-6 cm) and 5.3 cm (4.5/7 cm), respectively. The range of passive flexion was on average 81 degrees (range, 45-105 degrees ). Limping and a positive Trendelenburg's test were recorded in all patients and all also had to use walking aids. The outcome of surgery was evaluated as satisfactory by 35 % and as partially satisfactory by 43 % of the patients.


DISCUSSION
Resection arthroplasty is a reliable technique for pain reduction, but it results in a considerable alteration of hip function. Pain in the hip after surgery is bearable, as 80 % of our patients reported only mild or moderate pain alleviated by common analgetics, or complete absence of pain. This is in agreement with the results of Stoklasa (84 %) and Stedrý (79 %). However, the subjective evaluation of surgery by patients is different; Petty has reported 14 % of satisfied patients, while Ahlgren and Böhler described 100 % of satisfied patients. Hip stability and less shortening of the extremity are more important for patients' satisfaction than a certain mild degree of pain. The best subjective evaluation was reported by the patients who had resection at the femoral neck level and who also had the lowest average shortening of the extremity. But only 55 % of the satisfied or partially satisfied patients reported mild or no pain.


CONCLUSIONS
Resection arthroplasty is, in indicated cases, a reliable method which, in spite of certain drawbacks, produces good functional outcomes and makes the patients satisfied. It is, without doubt, an integral part of the current orthopedic surgery repertoire. We recommend a cautious approach to repeated attempts at THA reimplantation or to reconstruction procedures.