Autologous resurfacing

The Modified Hedgehog Technique to Repair Pure Chondral Shear-off Lesions in the Pediatric Knee

OBJECTIVE

The paediatric knee is prone to pure chondral shear-off lesions due to the developing osteochondral unit. Refixation of the chondral fragment is commonly done using metalwork or absorbable biomaterials. Both fixation methods come with biomaterial-related drawbacks. Earlier work on chondral allografts for cartilage repair in adults has shown successful osteochondral integration when the chondral allograft is treated with multiple incisions and then glued to the subchondral bone using fibrin glue. This is commonly referred to as the "hedgehog technique." This study investigates the feasibility of a modification of the hedgehog technique in autologous cartilage to repair shear-off lesions in children.

DESIGN

Three consecutive patients (aged 11, 12, and 14 years) with shear-off chondral fragments of 2, 5, and 8 cm² were treated using this modified hedgehog technique. The calcified side of the chondral fragments were multiply incised and trimmed obliquely for an interlocking fit in the defect site. Fibrin glue and, if indicated sutures, were applied to fix the fragment to the defect. In 1 patient, an anterior cruciate ligament (ACL) repair was also performed. Patients were evaluated clinically and by magnetic resonance imaging (MRI) up to 12 months postoperatively.

RESULTS

Twelve months after surgery, all patients reported no pain and showed complete return to sport and full range of motion. MRI showed no signs of fragment loosening.

CONCLUSIONS

The modified hedgehog technique is a feasible treatment option to repair pure chondral shear-off lesions in the paediatric knee. This was the first time this technique was used in autografting.

A novel press-fit minimally-invasive symphysiodesis technique

Objective

Instability of the pubic symphysis often results in a poor outcome and reduced mobility of the patient. In some cases, an arthrodesis of the pubic symphysis is required. Until today, there is no data published how many of these procedures are performed annually and there is also no data about the outcome after this extensive surgery.

Methods

We developed a novel surgical technique to address the arthrodesis of the pubic symphysis in a minimally invasive approach. Therefore, we used for this purpose modified instruments and performed the transplantation of a cylindrical bone substitute into the pubic symphysis, without an extensive approach or dissecting the anterior or posterior symphyseal ligaments.

Results

Using this novel technique, a minimally invasive symphysiodesis was achieved in radiological findings, after the procedure.

Conclusion

Thus, this actually minimally invasive surgical technique seems to be a promising advancement for the arthrodesis of the pubic symphysis.

Long-term results of reconstructing the joints' articular surface in the knee and ankle with the surgical diamond instrumentation (SDI)

PURPOSE

The surgical diamond instrumentation (SDI), a precise wet-grinding technology, promised contact healing of press-fit inserted bone and even hyaline cartilage, lacks medium- and long-term results. This retrospective study was conducted to identify risk factors associated with the failure of the technique and the subjective patient outcome.

METHODS

All patients treated for cartilage defects of the knee or ankle joint using the SDI technology between 2000 and 2012 with a follow-up > 1 year were included. Patients with general joint diseases or joint-related procedures, except for corrective osteotomies, were excluded. A standardized questionnaire (EQ-5D) and a questionnaire-based patient-reported outcome survey were used. Descriptive statistics were applied. A multivariate analysis examining risk factors for joint failure was performed. A p value < 0.05 was considered to indicate significant differences.

RESULTS

87 patients with autologous osteochondral transplantation (68 knee, 19 ankle) were included. The median age was 53 years (IQR 37.5-63.0 years) for knee and 36 years (IQR 27.5-54.0 years) for ankle joints. 57.9% of knee and 55.6% of ankle patients were female. Nine patients (8 knee, 1 ankle) had received arthroplasty. 93.3% of knee and 83.3% of ankle patients had an excellent function or minor disabilities. 73.3% of knee and 64.7% of ankle patients did not require pain medication. The mean EQ-5D score was 0.84 for knee and 0.77 for ankle. Patients with higher age were more likely to receive arthroplasty (p = 0.022).

CONCLUSIONS

The SDI technique provides promising results with excellent joint survival rates and satisfying patient-reported outcomes. Failure of the technique might be associated with higher age.

Autologous Transplantation of Press-fit Bone Cylinders in the Treatment of Pelvic Nonunion

The present study describes method for autologous bone transplantation to an area of nonunion at the pelvic ring in a way that ensures the best possible bone‐to‐bone interface (“press‐fit”) and provides optimal preconditions for the ingrowth of the bone graft. We modified a technique that has been used to transplant press‐fit bone‐baseplate‐cartilage cylinders for the repair of joint cartilage defects. The technique allows for precise harvesting of bone cylinders with a diamond‐coated and fluid‐cooled instrument. At the site where the graft shall be inserted, a cylindrical hole is created with a corresponding hollow diamond‐coated trephine. This ensures an optimal press‐fit implantation of the graft. The new surgical technique has been applied in four patients with nonunion of the pelvic ring. No intraoperative or postoperative complications occurred. In three patients, the procedure led to a reduction of pain and a higher level of mobility as well as a timely radiographic union (imaging not available for another patient). Our technique offers a valuable new treatment option for pelvic nonunion. The current article serves as a proof of concept. Future comparative studies will have to determine its value in detail.