Purpose

The literature indicates that the tibial component in total knee arthroplasty (TKA) should be placed in internal rotation not exceeding 18 to the line connecting the geometrical center of the proximal tibia and the middle of the tibial tuberosity. These landmarks may not be easily identifiable intraoperatively. Moreover, an angle of 18 is difficult to measure with the naked eye.

Purpose: Component malrotation is a recognized cause of post total knee arthroplasty (TKA) pain. The objective of this study was to evaluate the functional outcomes of TKA revision for component malrotation, and to compare it to revision surgeries for aseptic loosening as a control comparison group.

Method: Twenty four patients who had TKA revision due to component malrotation as the only objective abnormality were reviewed. Only patients with preoperative computerized tomography (CT) documentation of 3° or more malrotation of at least one of the components were included. Mean combined rotation was 6.8° (range, − 12 − 3) excessive internal rotation. Twenty four matched control patients had TKA revision due to aseptic loosening.

Results: Mean follow up was 37 months (range, 24–65). Mean interval from index surgery was 41 months (range, 24–65) for the study group and 98 months (range, 11–222) for the control group (p=0.0003). Preoperative Knee Society Score (KSS) improved by 49 points (range, 16–80) at 6 months postoperatively for the malrotation patients and by 39 (range, − 7–78) for the loosening patients (p=0.08). At last follow-up, KSS was 80 (range, 60–89) for the malrotation group and 75 (range, 26–90) for the loosening group (p=0.14).

Conclusion: We recommend the use of CT scans in evaluation of all patients with early painful TKA’s and no objective evidence of infection. When component malrotation is demonstrated, we believe the results of this study validate consideration of early revision.

Purpose: The literature regarding the outcome of total knee arthroplasty following distal femoral varus osteotomy is limited. The largest published series to date of eleven such patients suggested that medio-lateral constrained implants are commonly required as ligament balancing is difficult. This study presents mid-term outcomes of patients treated with total knee arthroplasty following distal femoral varus osteotomy at a single center.

Method: Twenty-two consecutive distal femoral varus osteotomies (21 patients) converted to total knee arthroplasties were reviewed at a mean follow-up of five years (range, two to 14 years). The mean duration between osteotomy and conversion to arthroplasty was 12 years (range, three to 21 years). In 14 patients (15 knees) the underlying etiology for the femoral osteotomy was primary knee osteoarthritis with valgus deformity, while in seven patients the procedure was performed to unload a fresh osteochondral allograft of either the lateral tibia (five patients) or femur (two patients). It is the authors’ routine to use posterior stabilized implants were used in all total knee arthroplasty surgeries. Femoral stems were used in six knees in which the bone quality was clinically determined by the surgeon to be sufficiently deficient to predispose to periprosthetic fractures, while the remaining sixteen knees were treated with unstemmed components. Modified knee society scores were used to evaluate the clinical outcomes preoperatively and at most recent follow-up.

Results: The mean knee society knee and function scores in surviving knees improved from 50 points (range, 10 to 75 points) and 50 points (range, 30 to 70 points) pre-operatively, to 91 points (range, 67 to 100 points) and 64 points (range, 50 to 70 points) at final follow-up, respectively. The mean arc of motion improved from 94 degrees (range, 70 to 115 degrees) to 114 degrees (range, 90 to 130 degrees). Two patients underwent revision arthroplasty for polyethylene wear and component loosening at eight and 11 years following the index arthroplasty, respectively. There were no fractures, infections or wound complications.

Conclusion: Total knee arthroplasty following distal femoral varus osteotomy reliably decreases pain and improves knee function. Standard posterior stabilized components provide satisfactory stability after appropriate ligamentous balancing, without the need for stemmed or highly constrained components in the majority of patients.

Purpose: Acetabular component revision in the context of large, contained bone defects with less than 50% host-bone-contact traditionally required roof reinforcement or antiprotrusio cages. Trabecular Metal (TM) cups (Zimmer, Warsaw, Indiana) may offer a viable treatment alternative. The objective of this study was to evaluate the clinical and radiological outcome of this mode of treatment.

Method: Fifty-four hip revision acetabular arthroplasty procedures performed with TM cups for contained defects offering ≤50% contact with native bone were prospectively followed. Average follow-up was 45 months (range 24–71). All patients were clinically and radiographically evaluated for evidence of loosening or failure.

Results: Contact with bleeding host bone ranged from 0 to 50% (average 23%). At latest follow up 43 (79.6%) arthroplasties had excellent or good results, 8 (14.8%) cases had medium or fair results and 3 cases (5.6%) had poor results. Two cups failed and had to be revised. Two additional cups had radiological evidence of probable loosening. Overall preliminary survivorship of the revision acetabulae was 96%. Complications included 4 dislocations and 1 sciatic nerve palsy.

Conclusion: Treatment of cavitary defects with less than 50% host-bone contact with using TM cups, without structural support by augments or structural bone grafts, is a viable option.

Purpose: Pelvic discontinuity associated with bone loss is a complex challenge in acetabular revision surgery. Reconstruction with anti protrusion cages, Trabecular Metal (Zimmer, Warsaw, Indiana) cups and morselized bone (Cup-Cage) constructs is a relatively new technique used by the authors for the past 6 years. The purpose of the study was to examine the clinical outcome of these patients.

Method: Thirty-two consecutive acetabular revision reconstructions in 30 patients with pelvic discontinuity and bone loss treated by cup cage technique between January 2003 and September 2007 were reviewed. Average clinical and radiological follow up was 38.5 ± 19 months (range 12 – 68, median 34.5). Failure was defined as component migration > 5mm.

Results: In 29 (90.6%) patients there was no clinical or radiographic evidence indicative of loosening at latest follow up. Harris Hip Scores improved significantly (p< 0.001) from 46.6 ± 10.4 to 78.7 ± 10.4 at 2 year follow up. In 3 patients the construct migrated at 1 year post surgery. One construct was revised to anti protrusion cage with a structural graft while the other was revised to a large Trabecular Metal cup. The third patient is scheduled for revision. Complications included 2 dislocations, 1 infection and 1 partial peroneal nerve palsy. Two patients died due to unrelated reasons at 1 and 3 years post surgery, respectively.

Conclusion: Treatment of pelvic discontinuity by Cup-Cage construct is a reliable option based on preliminary results which suggest restoration of the pelvic mechanical stability. However, patients should be followed closely in order to detect cup migration until satisfactory bony ingrowth into the cup takes place.

Objective: The purpose of this study was to survey and to evaluate our early results with the cementless ZMR hip prosthesis.

Methods and Patients: This modular system is designed to address the challenges and design goals of hip revision with off-the-shelf flexibility, proximal-distal extensive fixation and restoration of hip kinematics (offset, lengths and anteversion). The Taper femoral component is designed for distal fixation using a distal stem that is tapered to help obtain secure, consistent seating in the femoral canal, and splints that engage bone to provide rotational stability. The porous stem is designed to provide proximal or extensive (both proximal and distal) fixation. The geometry of the modular proximal body is designed to help preserve bone. The taper junction between the proximal body and distal stem allows for control of version of the implant. Eighteen ZMR taper hip prostheses were implanted between January 2004 and August 2005. The mean age of the 18 patients (13 females, 5 males) was 72 and the mean follow-up period was 10 months.

Results: Out of these 18 patients, 4 interventions were primary (DDH or pathological fractures) and 14 were revision procedures. In most (16) cases a taper stem was used. In 14 cases a total hip revision was performed, in 2 cases only the femoral stem was revised and in 2 cases a bipolar Hemiarthroplasty was done. Operative time averaged 187±33 minutes.

The stem displayed an excellent distal fixation, clinically and radiologically. Much less complications were noted, compared to earlier series. Three patients had postoperative infections – one case was after a 2 stage revision of an infected implant, one case was associated with a large hematoma due to excessive anticoagulation and another case was a superficial infection that resolved. Other complications included 2 (11%) early dislocations and one femoral nerve palsy. There were no intraoperative fractures of perforations and none of these complications necessitated implant removal.

Conclusion: The excellent distal fixation, simplicity of the operative technique and modularity of stem length and diameter, body size and offset, and anteversion, makes this system an attractive solutions for a wide variety of difficult femoral revisions. The high rate (11%) of early dislocations is still lower than other series with this system.

This study reviews our 13-years experience with Haas’s multiple-longitudinal osteotomy technique for correction of tibial deformities in children. In this procedure multiple longitudinal bi-cortical osteotomies are made parallel in the proximal tibia. The deformity is corrected by applying moderate force in the desired plane. Fixation is achieved with either a long cast or with “pins-in-plaster”.

Sixty osteotomies were performed in 37 children. Thirty-five cases had internal tibial torsion (ITT), 11 had external tibial torsion (ETT) and 14 had a Tibia Vara deformity. Twenty-one cases had Spastic Cerebral Palsy and 15 cases were associated with Clubfeet. One boy had bilateral tibia vara associated with SMED (Spondylo-meta-epiphyseal dysplasia). Twenty-two (36/7%) of the deformities had no underlying musculoskeletal conditions.

Thigh-foot angles were corrected by a mean of 24^° for ITT and −28° for ETT. Mean correction for tibia vara was 20°. Average anesthesia time for unilateral cases was 47 minutes. No neurologic or infectious complications, postoperative fractures or physeal damage occurred. There was one case of delayed union and 1 case of postoperative antecurvatum deformity. All 7 cases of postoperative recurrent deformities were associated with CP or SMED.

This technique is a simple, safe and efficient method for correcting tibial torsional and varus deformities for both healthy children and those with underlying conditions. It allows accurate alignment of different deformities with an uniform osteotomy technique, which preserves bone continuity and provides inherent stability, thus avoiding the use of internal fixation.