Dror Lakstein

Enhanced osseointegration of grit-blasted, NaOH-treated and electrochemically hydroxyapatite-coated Ti-6Al-4V implants in rabbits

Osseointegration, in terms of the bone apposition ratio (BAR) and the new bone area (NBA), was measured by backscattered electron imaging. The results were compared for four implant types: grit-blasted and NaOH-treated Ti-6Al-4V (Uncoated-NaOH), electrodeposited with hydroxyapatite without alkali treatment (ED-HAp), electrodeposited with hydroxyapatite after alkali treatment (NaOH-ED-HAp), and plasma sprayed with hydroxyapatite (PS-HAp). No heat treatment was done after soaking in NaOH. The implants were press fitted into the intramedullary canal of mature New Zealand white rabbits and analyzed, both at the diaphyseal and at the metaphyseal zones, either 1week or 12weeks after surgery. NaOH-ED-HAp already exhibited a higher BAR value than the ED-HAp at 1week, and was as good as the commercial PS-HAp at 12weeks. The NBA value for NaOH-ED-HAp at 12weeks was the highest. The higher content of octacalcium phosphate in NaOH-ED-HAp, as evident from the X-ray photoelectron spectroscopy analysis of the oxygen shake-up peaks, and the associated increase in the solubility of this coating in vivo are considered responsible for the enhanced osseointegration. Taking into account also the reduced occurrence of delamination and the inherent advantages of the electrodeposition process, electrodeposition of HAp following soaking in NaOH may become an attractive alternative for the traditional plasma-sprayed process for coating of orthopedic and dental implants.

Total Hip Arthroplasty in Patients With Down Syndrome

Hip osteoarthritis is prevalent in 8% to 28% of patients with Down syndrome. Presence of disabling hip pain is increased along with prolonged life expectancy, suggesting total hip arthroplasty (THA). Seven consecutive patients (9 hips) with Down syndrome underwent primary THA. Coxarthrosis was secondary to developmental hip dysplasia in 6 patients and slipped capital epiphysis in 1 patient. In 5 patients (7 hips), a previous hip surgery was performed. Average clinical and radiological follow-up was 9.9±6.4 years (range, 2-22.5 years; median, 9.3 years). Average patient age at THA was 34.8±7.5 years (range, 25- 47 years; median, 35.4 years). In 2 patients (3 hips), a trochanteric slide was used for the surgical approach, while a lateral transgluteal approach was used in the remaining patients. One-way analysis of variance test was used to compare Harris Hip Scores (HHS) at postoperative follow-up.Harris Hip Scores improved significantly (P=.008) from 4.1±15.1 (range, 18.5-65; median, 45) to 84.8.3±7.7 (range, 70-93; median, 85.8) at 4-year follow-up. Harris Hip Scores (average, 70.9±6.2; range, 66.5-80; median, 68) remained essentially unchanged (P=.43) at 8-year follow-up. Two patients required revision THA for stem loosening at 6 and 16 years post-THA, respectively. The first patient is 7 years post-revision and ambulates without aids. The second patient is 6.1 years post-revision and ambulates with a walker. Six of the THAs required a constrained liner. No dislocations or deep infections were encountered. At last follow-up, all patients had a functional range of motion without evidence of discomfort related to their THA.

Partial lateral patellar facetectomy as an alternative to lateral release in Total Knee Arthroplasty (TKA).

This study presents the selective use of partial patellar lateral facetectomy for maltracking during primary TKA, as an alternative to lateral release. Twenty three partial facetectomies were performed out of 191 TKAs (12%). Balanced tracking was achieved in 22 knees. At follow-up 2 patients had persistent anterior knee pain. Mean Knee Society score (KSS) was 94 and mean functional KSS was 86. Mean patellar score was 28. Patellar tilt angles were within 2 degrees in all but one knee. Patellar translation was within 2 mm in all cases. No complications were recorded. A control group of 46 matched patients had similar functional and radiographic results. If tracking is not satisfactory at the conclusion of TKA, our method of choice would be partial lateral facetectomy.

Primary Closure of Elective Toe Amputations in the Diabetic Foot—Is it Safe?

BACKGROUND Toe amputation is the most common partial foot amputation. Controversy exists regarding whether to primarily close toe amputations or to leave them open for secondary healing. The purpose of this study was to evaluate the results of closed toe amputations in diabetic patients, with respect to wound healing, complications, and the need for further higher level amputation. METHODS We retrospectively reviewed the results of 40 elective or semi-elective toe amputations with primary closure performed in 35 patients treated in a specialized diabetic foot unit. Patients with abscesses or necrotizing fasciitis were treated emergently and were excluded. Patients in whom clean margins could not be achieved due to extensive cellulitis or tenosynovitis and patients requiring vascular intervention were excluded as well. Outcome endpoints included wound healing at 3 weeks, delayed wound healing, or subsequent higher level amputation. RESULTS Out of 40 amputations, 38 healed well. Thirty amputations healed by the time of stitch removal at 3 weeks and eight had delayed healing. In two patients the wounds did not heal and subsequent higher level amputation was eventually required. CONCLUSIONS In carefully selected diabetic foot patients, primary closure of toe amputations is a safe surgical option. We do not recommend primary closure when infection control is not achieved or in patients requiring vascular reconstruction. Careful patient selection, skillful assessment of debridement margins and meticulous technique are required and may be offered by experienced designated surgeons in a specialized diabetic foot unit.

Does restoration of leg length and femoral offset play a role in functional outcome one year after hip hemiarthroplasty

BACKGROUND The objective of this study was to evaluate the correlation between specific joint biomechanical parameters and 1year functional outcome scores in elderly patients receiving hemiarthroplasty in the setting of intracapsular hip fractures. METHODS This is a retrospective, institutional registry based study. 168 hip hemarthroplasties were captured from October 2013 to June 2015. Patients were excluded based on contralateral hip surgery, perioperative complications or inadequate radiographs. 84 patients were alive at one year follow up. We compared mobility and pain scores to radiographically determined variations of leg lengths and femoral offset. We also compared the performance of fellowship trained arthroplasty surgeons to their non-fellowship trained counterparts. RESULTS The operated leg was a mean of 1.12±6.8mm longer than the contralateral. leg length discrepancy (LLD) was less than 10mm in 72 patients. Mean difference in offset between limbs was 0.25±3.3mm. The difference was within 5mm in 79 patients (94%). We found no statistically significant correlation between mobility or pain scores and variations in leg length or offset. We found significantly better performance of the arthroplasty surgeons in restoring leg length but no difference in offset reconstruction or functional benefit for the patient. CONCLUSIONS Our study was unable to demonstrate a significant relationship between leg length or femoral offset restoration and the patients ultimate functional recovery. Arthroplasty surgeons performed better in restoring leg length, but no associated functional advantage was seen.

Preoperative planning of total hip arthroplasty on dysplastic acetabuli.

Background When performing total hip arthroplasty (THA) on a dysplastic hip, proper positioning of the acetabular component may not allow for more than 70% coverage. Structural support in the form of an autograft or a high porosity metal augment may be necessary. The purpose of the study was to investigate the value of pre-operative templating and deformity classification in predicting cup coverage and the need for structural support. Methods 65 cases of THA for DDH were retrospectively analysed. 2 observers independently classified each dysplastic hip according to Hartofilakidis and determined the extent of cup coverage via templating software on pre-operative digital AP pelvic radiographs. Results Weighted kappa interobserver agreement was 0.68 for cup coverage and 0.76 for Hartofilakidis type. Structural support was necessary in 10 hips. No structural support was necessary in Hartofilakidis type 1, dysplasia cases. However, 27-30% of cases with type 2 or type 3 dysplasia required structural support. All cases with templated cup coverage of 65% or less required structural support. Templated coverage within 65-75% and over 75% resulted in 20% and 10% of patients receiving structural augmentation, respectively. Conclusions Pre-Operative planning for THA in the setting of hip dysplasia is crucial and can provide valuable insight to the need for column augmentation. However, the 3-D severity of the deformity may be underestimated in the 2-D radiographs.

Primary Closure of Toe Amputations in the Diabetic Foot - Is it Safe?

Abstract BACKGROUND: METHODS: RESULTS: CONCLUSIONS:

Precise technique for simple and accurate pip arthrodesis using a blunt KW technique

Proximal interphalangeal joint (PIP) arthrodesis is a very common procedure in the practice of foot and ankle surgeons. The standard technique recommends using a Kirschner wire (KW) with double sharp ends. Using this technique there are some complication that can be eliminated by small modification. The technique of proximal interphalangeal joint arthrodesis using a simple blunt KW on one side with an accurate placement and avoidance of metatarsophalangeal joint (MTPJ) penetration without the need for fluoroscopy is described. This technique is simple, reproducible, very economical and avoiding most of the complications attributed to the KW.