Postoperative Leg Length Research Articles

The Impact of Leg Length Discrepancy on Clinical Outcome of Total Hip Arthroplasty: Comparison of Four Measurement Methods

In a single-surgeon series of 119 patients with unilateral primary uncemented total hip arthroplasty, four leg-length discrepancy measurement methods (absolute, relative, trochanteric, standardized-trochanteric) were analyzed for their impact on WOMAC score, Oxford Hip Score and self-perceived leg-length discrepancy. After adjustment for age, gender and BMI, postoperative WOMAC scores correlated only with clinical absolute measurements of leg elongation (P=0.05). Self-perceived leg-length discrepancy corresponded best to the clinically measured relative leg-length discrepancy (11 mm perceived vs. 7 mm unperceived; P=0.04) while there was no significant correspondence with radiographic measurements or leg elongation magnitudes. Within the <10 mm range of mean postoperative leg length discrepancy in the studied series, its impact on the overall clinical satisfaction was detectable but not considerable.

Lesser trochanteric osteotomy in total hip arthroplasty for treating CROWE type IV developmental dysplasia of hip

The study was designed to evaluate the efficacy and safety of lesser trochanteric osteotomy for femoral shortening in total hip arthroplasty in treatment of 28 cases of CROWE IV developmental dysplasia of the hip (DDH). Patients underwent progressive femoral shortening at the level of lesser trochanteric to make reduction possible into the anatomical acetabulum in all hips. The results were collected and evaluated clinically and radiographically. The mean follow-up period was 55.3months. The average postoperative leg length discrepancy was eight millimetres for unilateral THA patients. A modified Merle d'Aubigné scale was improved from 9.3 preoperatively to 15.9 postoperatively. Sciatic nerve palsy was confirmed in two hips which resolved completely in sixmonths. The Trendelenburg sign was positive in two hips at the final follow-up. No revision surgery was required by the final follow-up. Lesser trochanteric osteotomy proved to be safe and effective in femoral shortening for treatment of CROWE IV DDH without the problem of nonunion at the site of osteotomy.

Pirogow’s Amputation: A Modification of the Operation Method

Introduction. Pirogow's amputation at the ankle presents a valuable alternative to lower leg amputation for patients with the corresponding indications. Although this method offers the ability to stay mobile without the use of a prosthesis, it is rarely performed. This paper proposes a modification regarding the operation method of the Pirogow amputation. The results of the modified operation method on ten patients were objectified 12 months after the operation using a patient questionnaire (Ankle Score). Material and Methods. We modified the original method by rotating the calcaneus. To fix the calcaneus to the tibia, Kirschner wire and a 3/0 spongiosa tension screw as well as a Fixateur externe were used. Results. 70% of those questioned who were amputated following the modified Pirogow method indicated an excellent or very good result in total points whereas in the control group (original Pirogow's amputation) only 40% reported excellent or very good result. In addition, the level of pain experienced one year after the completed operation showed different results in favour of the group being operated with the modified way. Furthermore, patients in both groups showed differences in radiological results, postoperative leg length difference, and postoperative mobility. Conclusion. The modified Pirogow amputation presents a valuable alternative to the original amputation method for patients with the corresponding indications. The benefits are found in the significantly reduced pain, difference in reduced radiological complications, the increase in mobility without a prosthesis, and the reduction of postoperative leg length difference.

Leg-Length Discrepancy After Revision Hip Arthroplasty: Are Modular Stems Superior?

We retrospectively reviewed data for 79 consecutive patients who underwent revision hip arthroplasty using cementless femoral stems at our center between September 2008 and November 2010. Two cohorts were included, one using MP (modular) femoral stems and the other using Wagner (monoblock) femoral stems. We assessed leg-length discrepancy (LLD) before and after revision and compared the occurrence of leg-length inequality between the 2 cohorts. We found that the incidence of LLD was high in revision hip arthroplasty and that leg shortening was more common than lengthening. Both acetabular and femoral sides contributed to postoperative LLD. Appropriate placement of the femoral components was most critical in adjusting LLD. We also found that compared with monoblock stems, modular stems made adjustment of postoperative leg length easier.

Trunnion design and femoral head diameter increase corrosion at the taper interface in retrieved large-diameter metal-on-metal total hip arthroplasty

s / International Journal of Surgery 10 (2012) S53–S109 S55 ABSTRACTS 0128: TRUNNION DESIGN AND FEMORAL HEAD DIAMETER INCREASE CORROSION AT THE TAPER INTERFACE IN RETRIEVED LARGEDIAMETER METAL-ON-METAL TOTAL HIP ARTHROPLASTY Adam Hexter , Anna Panagiotidou , Gordon Blunn , John Skinner , Alister Hart . 1 London Implant Retrieval Centre, Imperial College London, London, UK; Royal National Orthopaedic Hospital, London, UK Aim: To characterise corrosion at the taper interface in large diameter metal-on-metal total hip arthroplasty and the effect of femoral head diameter. Method: Corrosion was qualitatively assessed using a peer-reviewed grading system for 111 components from three different manufacturers (ASR, BHR, Durom). Unexpectedly a ridged appearance was commonly observed on the female taper surfaces, which corresponded exactly with the ridges of the trunnion surface. A new grading system was created to measure this imprinting phenomenon. Results: 92% of the components experienced corrosion, with at least moderate corrosion seen in 61%. The manufacturer did not influence corrosion both for head components (p1⁄40.52) and trunnions (p1⁄40.20). A strong positive correlation (r1⁄40.776, p1⁄40.01) was observed between the imprinting scores and corrosion scores. Larger head diameters showed higher corrosion (r1⁄40.241, p1⁄40.02). Conclusions: Corrosion affects all manufacturers and is associated with the presence of ridges on the female taper surface. It appears that the rough surface of the trunnion causes extensive mechanical damage at the female taper surface and creates a hostile corrosive environment. Femoral head diameter correlates with corrosion, which is clinically significant considering the increasing use of larger head sizes. Future work must now clarify the optimum trunnion design and femoral head diameter. 0129: WEAR AND CORROSION AT THE TAPER INTERFACE IN RETRIEVED ASR XL METAL-ON-METAL TOTAL HIP ARTHROPLASTY Adam Hexter , Anna Panagiotidou , Gordon Blunn , Johann Henckel , John Skinner , Alister Hart . 1 London Implant Retrieval Centre, London, UK; Royal National Orthopaedic Hospital, London, UK Aim: To quantify wear at the ASR XL taper interface and determine the relationship between taper corrosion and blood metal ions. Method: Corrosion was qualitatively assessed using a peer-reviewed grading system for 52 ASR XL femoral head components. Blood metal ion levels in hips showing at least moderate corrosion was compared with those without moderate corrosion. Profilometry was performed in hips (n1⁄412) that failed due to debris-induced synovitis in the presence of low bearing surface wear (<10mm/year combined head/ cup). Results: 98% of the components were corroded, with at least moderate corrosion observed in 66%. Corrosion did not influence the levels of blood cobalt (p1⁄40.16) and chromium (p1⁄40.12) ions. The median volumetric loss was 3.08mm3 (range: 0.61-9.44) and the maximum wear depth ranged from 14-85mm. Conclusions: Metal debris is implicated in the formation of soft-tissue reactions and we show that taper wear and corrosion is substantial. Currently there is no other culprit that could account for the higher failure rate of the ASR XL when compared to resurfacing. Greater corrosion did not equate to increased metal ion levels. Future work must determine the relative contributions of the bearing surface and taper interface tomaterial loss and blood metal ions. 0157 WINNER OF ORTHOPAEDIC RESEARCH UK PRIZE: ACCURACY OF DIGITAL TEMPLATING IN TOTAL HIP REPLACEMENT AND POSTOPERATIVE LEG LENGTH INEQUALITY John Kyle , Anthony McWilliams , Richard Grogan . 1 James Cook University Hospital, Middlesbrough, UK; Bradford Royal Infirmary,

Accuracy of digital templating in total hip replacement and post-operative leg length inequality

Accuracy of digital templating in total hip replacement and post-operative leg length inequality

Is the Dislocation Rate Higher after Bipolar Hemiarthroplasty in Patients with Neuromuscular Diseases?

Patients with neuromuscular disease reportedly have a higher incidence of postoperative dislocation after bipolar hemiarthroplasty. Although the literature has focused on a high prevalence of preoperative neurologic conditions in patients who had dislocations after bipolar hemiarthroplasties, the relative incidence of dislocation in patients with neuromuscular disease and without is unclear. We therefore (1) asked whether the incidence of postoperative dislocation after bipolar hemiarthroplasty was greater in patients with neuromuscular disease than for those without, and (2) whether function differed between the two groups, and (3) explored potential risk factors for dislocation in two groups. We retrospectively reviewed 190 patients who underwent bipolar hemiarthroplasties for fracture of the femoral neck between 1996 and 2008. Of the 190 patients, 42 had various neuromuscular diseases and 148 had no history of neuromuscular disease. Intraoperative stability was tested and posterior soft tissue repair was performed in all patients. We determined the incidence of dislocation, postoperative leg length discrepancy, and femoral offset in patients with or without neuromuscular disease. The incidence of dislocation was 2.6% in all patients. We observed similar rates of dislocation in the two groups: 4.8% (two of 42 hips) in patients with neuromuscular disease and 2.0% (three of 148 hips) in patients without neuromuscular disease. In femoral neck fractures in patients with neuromuscular disease, careful preoperative management and operative technique such as a posterior soft tissue repair might decrease the risk of postoperative dislocation; therefore, we consider the bipolar hemiarthroplasty a reasonable treatment option. Level III, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Functional and Radiological Evaluation of a Simple Intra Operative Technique to Avoid Limb Length Discrepancy in Total Hip Arthroplasty

We aimed to assess the radiological and functional outcome of total hip arthroplasty performed using a simple technique for intra-operative leg length assessment. The comparative group was made up of patients receiving total hip arthroplasty prior to introduction of the technique. Fifty patients were studied in each group. The pre- and 3 month post-operative leg length difference (LLD) was measured radiologically along with pre- and 12 months post-operative Oxford hip scores (OHS) and University of California Los Angeles (UCLA) activity scores.There were no statistically significant differences in pre-operative parameters between the two groups. The mean LLD in the new technique group was 0.46 mm which was significantly less than in the control group (p< 0.001). Post operative OHS values were worse when shortening or lengthening was >5 mm in both groups. UCLA activity scores were significantly better in the new technique group than in the control group (p< 0.001). The overall radiological and functional outcome of the patients was better in the new technique group.Functional outcome is related to small differences in leg length and our simple new technique can be used to control leg length intraoperatively.

Total hip arthroplasty offset measurement: Is C T scan the most accurate option?

Femoral offset is difficult to precisely evaluate with conventional X-ray techniques. Femoral offset characterizes the balance between body weight and the resistance provided by the abductor muscles. Total hip arthroplasties should respect this balance. Computed tomodensitometry (CT-scan) is more accurate than conventional X-ray to evaluate femoral offset. Sixty-one patients who received unilateral total hip arthroplasties were prospectively included in the study. Femoral offset was measured by three-dimensional CT-scan reconstruction using the "Hip Plan" (Symbios) software. Offset was also determined with conventional X-ray and results were compared. This software can be used to measure leg length by frontal telemetry. It was developed for preoperative-planning of cementless femoral stem implants with modular necks of various lengths and angles. All pre- and postoperative measurements were made according to the same protocol. Femoral offset values in this study were very similar to anatomical values found in the literature. They were significantly higher than values obtained by conventional X-ray by an average of 8%. Implantation of hip replacements resulted in a significant increase in offset (1.88+/-4.71 mm) with a slight variation in leg length. Pre- and postoperative leg length increased slightly in the operated leg by an average of 1.66+/-5.63 mm. Seventeen percent of these femurs had high offset associated with small or average sized proximal medullary canals. This preoperative planning software made it possible to identify these difficulties and to adapt implant components using modular long 8 degrees varus necks to restore high offset. In most of these cases, only small femoral stems could be implanted because of the small size of the intramedullary femoral canal. These individual differences were identified with 3D CT-scan reconstruction and included in the preoperative planning. Moreover, leg length could also be evaluated with this method and included in the preplanning. Compared to conventional X-ray, measurements obtained with this preoperative planning method using 3D CT-scan reconstruction are easy to obtain and not dependent upon test conditions because the frame is placed on the femoral axis. Measurements are not influenced by position inconsistencies or if the hip is fixed in external rotation. The significant number of cases with above average offset confirms the importance of obtaining these measurements and the necessity of adapting the strategy in these cases by using lateralized stems, or, as in our series, modular necks to adjust femoral offset and neck angle. Level III diagnostic prospective study.

The Accuracy of Preoperative Templating in Cementless Total Hip Arthroplasty

We evaluated the accuracy and clinical usefulness of preoperative templating in 109 cementless total hip arthroplasties. The size of the prosthesis was exactly predicted in 46 (42.2%) acetabular and 75 (68.8%) femoral components. The accuracy increased to greater than 90% if the prosthesis size was within 1 or 2 sizes (above or below) for femoral component and acetabular components, respectively. Having a contralateral total hip arthroplasty as a guide for preoperative templating was associated with greater accuracy in predicting the femoral component size only. Eighty-eight percent of the acetabular components were oriented inside the presumed safe range for inclination; 42% of the acetabular components were in the presumed safe range of anteversion. The mean postoperative leg length discrepancy was 0.9 ± 6.8 mm; 93.5% had a discrepancy within 10 mm.

Computed Tomography-based Surgical Navigation for Hip Arthroplasty

Component malpositioning and postoperative leg length discrepancy are the most common technical problems associated with total hip arthroplasty (THA). Surgical navigation offers the potential to reduce the incidence of these problems. We reviewed 317 patients (344 hips) that underwent THA using computed tomography-based surgical navigation, including 112 THAs using a simplified method of measuring leg length. Guided by the navigation system, cups were placed in 40.8 degrees +/- 2 degrees of operative abduction (range, 35 degrees -50 degrees) and 30.8 degrees +/- 3.2 degrees (range, 19 degrees -43 degrees) of operative anteversion. We subsequently measured radiographic abduction on plain anteroposterior pelvic radiographs and calculated abduction and anteversion. Radiographically, 97.1 % of the cups were in the safe zone for abduction and 92.4% for anteversion. The mean incision length was less than 8 cm for 327 of the 344 hips. Leg length change measured intraoperatively was 6.6 +/- 4.1 mm (range, -2-22), similar to measurements from the pre- and postoperative magnification-corrected radiographs. Computer assistance during THA increased the consistency of component positioning and allowed reliable measurement of leg length change during surgery.

The anterolateral approach in supine position for minimally invasive implantation of hip endoprostheses

Since September 2004 patients with primary THR are operated minimally invasive at our department. 350 implantations were carried out using the modified anterolateral Watson-Jones approach in supine position till now. For this method it is necessary to cover both legs sterilely and to use an OR table where it is possible to tilt the legs down, to perform adduction, external rotation and hyperextension during the preparation of the shaft. Besides theminimization of the surgical approach (skin incision between 7 and 12 cm) the main criterion of the minimal invasiveness is the preservation of the gluteal minimus and medius tendon insertions. Patient positioning and the surgical procedure with modified shaft rasps with double offset and use of the manipulation rasps as trial prostheses are presented. The complication rate was 2.9% (4 shaft fissures, 4 postoperative dislocations, one early infect, one post-traumatic trochanter fracture). Intraoperative trochanter fracture was not stated. When comparing both methods no differences arose regarding the postoperative hematocrit and haemoglobin level or the need for blood substitution, no further difference in the positioning of cups and stems, the postoperative leg length, the offset and the rotation centre of the hip. Tips and tricks from the experiences made till now are discussed. Patients with minimally invasive surgery on the 2nd hip and a conventional operation in earlier years were asked for their opinion using a standardized questionnaire and results were evaluated. Questions were asked about the postoperative pain, support needed during the first postoperative days, the use of crutches and walking up stairs, the skin incision and an overall assessment of the preferred operation method. In all respects a clearly increased patient satisfaction has been noticed for the minimally invasive procedure, with especially remarkable results for getting out of the bed on the 1st postoperative day, faster walking without crutches and easier walking up and down stairs.

Single-incision Anterior Approach for Total Hip Arthroplasty on an Orthopaedic Table

Dislocation remains the leading early complication of total hip arthroplasty; surgical approach and implant positioning have been recognized as factors influencing total hip arthroplasty stability. We describe a total hip arthroplasty technique done through a single, tissue sparing anterior approach that allows implantation of the femoral and acetabular components without detaching or sectioning any of the muscles and tendons around the hip joint. A series of 437 consecutive, unselected patients who had 494 primary total hip arthroplasty surgeries done through an anterior approach on an orthopaedic table from September 1996 to September 2004 was reviewed. There were 54 hybrid and 442 uncemented hips in the 437 patients (57 bilateral). The average patient age was 64 years. Radiographic analysis showed an average abduction angle of 42 degrees , with 96% in the range of 35 degrees to 50 degrees abduction. The average cup anteversion was 19 degrees with 93% within the target range of 10 degrees to 25 degrees . Postoperative leg length discrepancy averaged 3 +/- 2 mm (range, 0-26 mm). Three patients sustained dislocations for an overall dislocation rate of 0.61%, and no patients required revision surgery for recurrent dislocation. There were 17 operative complications, including one deep infection, three wound infections, one transient femoral nerve palsy, three greater trochanter fracture, two femoral shaft fractures four calcar fractures, and three ankle fractures. Operative time averaged 75 minutes (range 40-150 minutes), and the average blood loss was 350 mL (range, 100-1300 mL). The mean hospital stay was 3 days (range, 1-17 days). The anterior approach on the orthopaedic table is a minimally invasive technique applicable to all primary hip patients. This technique allows accurate and reproducible component positioning and leg-length restoration and does not increase the rate of hip dislocation. Therapeutic study, Level IV-1 (case series). See the Guidelines for Authors for a complete description of levels of evidence.

Saphenous Vein Harvest With SaphLITE System Versus Conventional Technique: A Prospective, Randomized Study

Minimally invasive saphenous vein harvest (MIVH) techniques have been evaluated and reported with heterogeneous results. The aim of this study was to evaluate the efficacy of MIVH on the outcomes of postoperative leg wound healing and pain using the SaphLITE retractor system. Two hundred twenty-five patients undergoing elective coronary artery bypass grafting surgery were randomized to receive either SaphLITE vein harvest (SVH) or conventional open vein harvest (OVH). There were no significant differences between the two groups in demographics, postoperative mortalities and major complications. For SVH group and OVH group, total leg wound length was 18.33 +/- 7.93 cm vs 46.10 +/- 15.63 cm (p < 0.001), and vein harvest time was 50.70 +/- 16.55 minutes vs 40.35 +/- 16.43 minutes (p < 0.001). In-hospital leg wound healing disturbance (LWHD) rate was 4.7% for SVH group and 1.7% for OVH group (p = 0.190). Delayed LWHD rate was 16.0% for SVH group and 39.5% for OVH group (p < 0.001). Combined, LWHD rate was 20.8% for SVH group and 41.2% for OVH group (p = 0.001). There was no significant difference in the worst postoperative leg wound pain or length of hospital stay between the 2 groups. Double-blinded histologic examinations revealed normal vascular structure in the harvested veins from both groups. Our study demonstrated that harvesting saphenous vein with SaphLITE retractor system is a good technique which is associated with reduced rate of delayed LWHD, preserved venous structural integrity, and acceptable harvest speed.

Cementless Total Hip Replacement Arthroplasty with Subtrochanteric Shortening Osteotomy in Crowe IV Developmental Dysplasia of the Hip

Purpose: The purpose of the current study is to introduce a surgical technique of total hip arthroplasty, by which a postsurgical neurologic deficit can be prevented and excellent clinical and radiological outcome can be obtained in patients with Crowe IV developmental dysplasia of the hip. Materials and Methods: Twelve hip joints underwent hip joint arthroplasty at our hospital between October 1995 and November 1997 due to hip joint arthritis secondary to developmental dysplasia of the hip. Among them six hip joints of five patients which belonged to the Crowe Classification IV were operated using cementless total hip arthroplasty with subtrochanteric shortening osteotomy. The medical records and radiographs of these five patients were reviewed. The average follow up period was 61.2 months (range of 40 to 77 months). Preoperative Harris hip score ranged from 61 to 71 (average, 66.2) points. Leg length discrepancy ranged from 2.0 to 5.5 (average, 4.1) cm. Results: Harris Hip Score was improved to 95.3 (87 to 100) points at the last follow up examination. The postoperative leg length was same bilaterally in five cases except for one case. Bone union in the osteotomy site was obtained three months after surgery. The radiolucent area and findings of movement of the acetabular cup were not observed. Subcidence of the femoral stem or pedestal formation was not observed in five cases. In one case, revision was done for the subcidence of 5 mm or more with radiolucent line around the entire stem and pedestal formation at 48 months postoperatively. One case showed femoral nerve paralysis immediately after the surgery, which recovered completely in six months after the surgery. Conclusion: This surgical technique is a useful method in total hip arthroplasty for the Crowe IV developmental dysplasia of the hip without permanent neurologic deficit.

Risk factors for dislocation of a cementless total hip endoprosthesis--a statistical analysis

This retrospective study aimed at the statistical identification of risk factors for dislocation for a certain cementless hip endoprothesis. At our department 2605 primary total hip arthroplasties were performed between 1987 and 1997. In 40 patients (1.5%) a dislocation occurred. These patients were compared with a control group matched in number. No difference was found in both groups with respect to age, height, weight, body-mass index, and diagnosis. A tendency was found that more males were involved in the dislocation group. There were more previous operations found in this group (p = 0.005). Also significant was the fact, that patients in the dislocation group more often had epidural anaesthesia (p = 0.02), more often the implantation of the smaller 28-mm head (vs. 32 mm) (p = 0.02), and a higher inclination angle of the acetabular component (p = 0.02). No difference was found in terms of the surgeons experience, the postoperative leg length, femoral offset, medialisation, cranialisation and antetorsion of the acetabular component. Dislocation after total hip arthroplasty is a multifactorial complication. With the use of the Alloclassic/Zweymüller total hip endoprothesis, a higher risk for dislocation was found for patients with previous hip surgery, the use of the smaller endoprosthesis head, a high acetabular inclination angle, and in the use of epidural anaesthesia.

Results of a method of leg-length equalization for patients undergoing primary total hip replacement

The postoperative leg-length discrepancy was determined radiographically for a consecutive series of 351 patients (408 hips) who underwent bilateral or unilateral primary total hip replacement using a single method of leg-length equalization by preoperative planning with overlay templates. The method of equalization was performed by a measurement of the femoral head and neck segment to be resected from a reference point at the superior aspect of the dislocated femoral head. The amount of femoral bone resected was determined preoperatively by determining the dimensions of the acetabular component thickness and the femoral component head and neck height that would be replacing this resected bone and adjusting this distance for any preexisting leg-length discrepancy. Using this leg-length equalization method, the length of the modular femoral head nec was chosen preoperatively, rather than using soft tissue tension across the prosthetic hip joint to determine whether the leg lengths were equal. Postoperative leg lengths were determined radiologically from a measurement from the acetabular teardrop to the lesser trochanter. Ninety-seven percent of the patients had a postoperative leg-length discrepancy that was less than 1 cm, and 86% had a leg-length difference that was 6 mm ( 1 4 inch) or less. The average postoperative discrepancy for these 351 patients was 1 mm.

Femoral nerve lesion in total hip replacement: an experimental study.

A total of 20 hip joints of 10 non-fixed corpses were examined within 48 h of death to measure the pressure below the inguinal ligament simulating the surgical conditions during total hip arthroplasty. The purpose of this study was to assess the influence of various leg positions and insertion techniques of retractors during the surgical procedure for total hip replacement in order to detect supposed causes for indirect pressure injuries of the femoral nerve. The obtained results verified no increase of pressure in the inguinal canal which could explain an indirect injury of the femoral nerve. If the retractor is inserted correctly at the anterior acetabular rim, the pressure in the lacuna musculorum can even be reduced, and furthermore, the femoral nerve is protected by the iliopsoas muscle. Femoral nerve lesions which have been published so far can only be explained by an incorrect use of instruments or implants (e.g., screws, cement, acetabular cup) or an extreme postoperative leg length discrepancy.

Leg Length Discrepancy in Total Hip Arthroplasty

After conducting a thorough literature review, we realized that no consensus exists regarding the definition of a significant postoperative inequality. Whereas some investigators quantitate the disparity, accepting as much as 2.0 cm or in some cases less, others define a significant disparity as one that promotes adverse functional effects postoperatively. This lack of a consistent definition reflects the wide disparity of opinion regarding the problem of postoperative leg length inequalities in total hip surgery. Although the literature may lack consistency, it does reflect the collective experience of many surgeons and provides valuable insight when approaching the issue of limb lengths in reconstructive surgery of the hip. We offer the following suggestions: 1. Begin with a thorough history and physical examination. Question the patient as to whether he or she actually perceives a leg length inequality. 2. Be aware of apparent leg length discrepancies in patients with hip disease. The perceived limb shortening is usually the result of a fixed adduction contracture with little true shortening. 3. Develop a consistent approach of evaluation preoperatively, intraoperatively, and postoperatively. Employ reliable and convenient clinical measures and radiographic techniques. A method of intraoperative assessment is mandatory. 4. Redundancy in the system helps to minimize error. Good preoperative planning does not supplant the need for intraoperative assessment and vice versa. 5. Address the issue of offset in preoperative planning. Anticipate its misleading effects on intraoperative evaluation. 6. Mention potential inaccuracies regarding limb length reconstruction in total hip surgery as part of a routine preoperative evaluation. Patients' expectations should be high but temporized with realism.

Leg Length Equalization During Total Hip Replacement

A method of equalization of leg lengths during total hip replacement surgery was developed which utilizes the concept of equalizing the vertical dimensions of the resected femoral head and neck segment and the remaining hip joint cartilage space, which are removed during the procedure, with the vertical dimensions of the femoral and acetabular prostheses, which are implanted into that void. This was accomplished by determining the dimensions of the prostheses from careful preoperative templating technique and by using a simple arithmetic formula to determine the level of the femoral neck osteotomy. The level of the osteotomy was made by a measurement from the top of the dislocated head of the femur to the medial femoral neck calcar. The radiologic postoperative leg length differences of a consecutive series of 84 patients undergoing primary total hip replacement using this method were determined. The average discrepancy was 2.8 mm. Seventy-five patients (89%) were found to have a postoperative leg length discrepancy of 6 mm (1/4 inch) or less. Six patients (7%) had a discrepancy of 7 to 13 mm, and only three patients (4%) had more than 13 mm (1/2 inch) leg length difference. Using this technique only two patients (2.5%) with unilateral hip replacements had leg lengthening of more than 6 mm.