Total knee arthroplasty for osteoarthritis secondary to extra-articular malunions

SummaryIntroductionPost-traumatic total knee arthroplasty for extra-articular malunion requires correction of the deformity, either through asymmetrical bone resection (possibly inducing ligaments imbalance) or osteotomy at the time of arthroplasty. We report the results of a continuous multicenter, retrospective series of 78 patients (18 implants with osteotomy) with a mean 4 years of follow-up. The hypothesis is that the selected procedure requires to be based on the deformity's location and severity.PatientsWith a mean age of 63 years (younger in the osteotomy group), 38 patients had femoral malunion, 36 had tibial malunion, and four had a combined malunion. There were 70 frontal deformities (48 varus and 22 valgus) and 10 rotational deformities, often diaphyseal, four of which more than 20°. Twelve patients had a history of infection; eight had frontal laxity greater than 10°, and 15 a limited range of motion in flexion. In 70 cases, semi- or nonconstrained implants were used, and in eight cases more constrained implants, including four hinge prostheses.ResultsWe observed two deep infections, one case of avulsion of the extensor mechanism, and two cases of aseptic loosening with femoral malunion and varus deformity. Two osteotomies resulted in nonunion, one with internal fixation devices mobilization requiring revision using extension rods. The function and pain scores were significantly improved. The mobility improvements were moderate but did not compromise the surgical procedure main objective. The preoperative hip-knee angle was corrected with both techniques. Only the function score gain was greater for the isolated arthroplasty procedures.Discussion and conclusionThe indications for arthroplasty alone were extended to 20° varus and 15° valgus, with no major residual laxity. Beyond 10°, hinge prosthesis should be available. Associated osteotomy can correct rotational deformities that cannot be compensated with bone cuts. In deformities that are close to the joint, osteotomy facilitates implantation of moderately constrained prosthesis. This indication is based on CAT scan rotational deformities measurements because rotational deformities require an osteotomy, and/or the presence of extraligamentous deformity that cannot be reduced with collateral ligaments surgical release.Level of evidenceLevel 4. Non-controlled retrospective study

Iliac crest bone graft harvesting complications: A case of liver herniation

SummaryThe iliac crest is an easily accessible donor site offering a relatively large and safe supply of bone. There are however possible complications; residual pain frequently, and more rarely herniation. This latter's true incidence is unknown in a literature review, which found 15 articles. We report a case of liver herniation in a 64-year-old overweight lady after harvesting bone from her iliac crest. The clinical diagnosis was confirmed by CT scan. Despite an appropriate surgical repair, the hernia recurred. This serious complication of bone harvesting from the iliac crest, and possible other undesirable events described, prompted reconsideration of our harvesting techniques, and the use in our unit of bone substitutes or cell therapy to fill bone defects

Pelvis and total hip arthroplasty acetabular component orientations in sitting and standing positions: Measurements reproductibility with EOS imaging system versus conventional radiographies

SummaryIntroductionThe literature has recently underlined the interest of pelvic and acetabular component orientation measurements in the standing and sitting position. Radiographic follow-up of total hip arthroplasty (THA) is based on standard AP and lateral X-rays. The use of EOS™ 2D imaging system reduces patient's radiation exposure compared to conventional X-rays. However, using this system, the validity and reproducibility of angular measurements, have not been studied yet for the measurement of pelvic and acetabular parameters in patients with THA.HypothesisThe EOS™ 2D imaging system offers similar advantages to conventional X-rays in the measurement of pelvic and acetabular orientation parameters which are commonly used.Patients and methodFive angular parameters characterizing pelvic tilt and acetabular cup orientation were determined using the same digital measurement Imagika™ software based on two series of standard X-rays and EOS™ 2D images acquired in both standing and sitting positions. Radiographs from 50 patients with unilateral THA were measured three times by two observers. Intra- and interobserver reproducibility using each method was independently studied then paired comparison was performed.ResultsThe ICC and Spearman rank correlation coefficient demonstrated an excellent EOS/conventional X-ray correlation. According to the parameters, the mean difference between these two imaging modalities ranged from 0.30° to 3.43° (P<0.05). The intra- and interobserver variability ranged from±2.97° to±6.46° using the EOS™ imaging system and from±4.26° to±10.22° using conventional X-rays (P<0.05).DiscussionThe EOS™ 2D imaging system may replace conventional X-rays in the assessment and monitoring of pelvic and acetabular cup orientation in THA.Level of evidenceLevel III. Prospective diagnostic study