Metal Resurfacing Inlay Implant for Osteochondral Talar Defects After Failed Previous Surgery: A Midterm Prospective Follow-up Study

BACKGROUND

Treatment of osteochondral talar defects (OCDs) after failed previous surgery is challenging. Promising short-term results have been reported with use of a metal resurfacing inlay implant.

PURPOSE

To evaluate the midterm clinical effectiveness of the metal implant for OCDs of the medial talar dome after failed previous surgery.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

We prospectively studied all patients who met the inclusion criteria and received a metal resurfacing inlay implant between 2007 and 2014. The primary outcome measure was implant survival, as measured by reoperation rate. Secondary outcome measures were numeric rating scales for pain at rest and during walking, running, and stair climbing; the Foot and Ankle Outcome Score (FAOS); the American Orthopaedic Foot and Ankle Society Ankle Hindfoot Scale; the 36-Item Short Form Health Survey (SF-36); return to work and sports; and radiographic evaluation.

RESULTS

This study included 38 patients with a mean age of 39 years (SD, ±13 years) and a mean follow-up of 5.1 years (SD, ±1.5 years). Two patients (5%) underwent revision surgery by means of an ankle arthrodesis (2 and 6 years postoperatively). In 8 patients, computed tomography scanning was conducted to assess postoperative complaints. These scans showed impression of the tibial plafond (n = 4), a small tibial cyst (<2.5 mm; n = 1), and cyst formation around the implant screw (n = 4). A total of 21 reoperations were performed, including medial malleolar screw removal (n = 12), arthroscopic removal of bony anterior impingement (n = 7), and calcaneal realignment osteotomy (n = 2). All secondary outcome measures improved significantly, apart from pain at rest, the FAOS symptoms subscale, and the SF-36 mental component scale. The mean time for return to sport was 4.1 months (SD, ±3 months), and 77% of patients resumed sporting activities postoperatively. Only 1 patient did not return to work postoperatively. Radiographs at final follow-up showed cyst formation (n = 2), subchondral periprosthetic radiolucency (n = 2), and non-preexisting joint space narrowing (n = 2).

CONCLUSION

This study shows that the metal implant is an effective technique when assessed at midterm follow-up for OCDs of the medial talar dome after failed previous surgery.

Analysis of deformity in scaphoid non-unions using two- and three-dimensional imaging

Pre-operative assessment of the deformity in scaphoid non-unions influences surgical decision-making. To characterize deformity, we used three-dimensional computed tomographic modelling in 28 scaphoid non-unions, and quantified bone loss, dorsal osteophyte volume and flexion deformity. We further related these three-dimensional parameters to the intrascaphoid and capitate-lunate angles, and stage of scaphoid non-union advanced collapse assessed on conventional two-dimensional images and to the chosen surgical procedure. Three-dimensional flexion deformity (mean 26°) did not correlate with intrascaphoid and capitate-lunate angles. Osteophyte volume was positively correlated with bone loss and stage of scaphoid non-union advanced collapse. Osteophyte volume and bone loss increased over time. Three-dimensional modelling enables the quantification of bone loss and osteophyte volume, which may be valuable parameters in the characterization of deformity and subsequent decision-making about treatment, when taken in addition to the clinical aspects and level of osteoarthritis.

TYPE OF STUDY/LEVEL OF EVIDENCE

Level IV.

Effects of Pulsed Electromagnetic Fields on Return to Sports After Arthroscopic Debridement and Microfracture of Osteochondral Talar Defects: A Randomized, Double-Blind, Placebo-Controlled, Multicenter Trial

BACKGROUND

Osteochondral defects (OCDs) of the talus usually affect athletic patients. The primary surgical treatment consists of arthroscopic debridement and microfracture. Various possibilities have been suggested to improve the recovery process after debridement and microfracture. A potential solution to obtain this goal is the application of pulsed electromagnetic fields (PEMFs), which stimulate the repair process of bone and cartilage.

HYPOTHESIS

The use of PEMFs after arthroscopic debridement and microfracture of an OCD of the talus leads to earlier resumption of sports and an increased number of patients that resume sports.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 1.

METHODS

A total of 68 patients were randomized to receive either PEMFs (n = 36) or placebo (n = 32) after arthroscopic treatment of an OCD of the talus. The primary outcomes (ie, the number of patients who resumed sports and time to resumption of sports) were analyzed with Kaplan-Meier curves as well as Mann-Whitney U, chi-square, and log-rank tests. Secondary functional outcomes were assessed with questionnaires (American Orthopaedic Foot and Ankle Society ankle-hindfoot score, Foot and Ankle Outcome Score, EuroQol, and numeric rating scales for pain and satisfaction) at multiple time points up to 1-year follow-up. To assess bone repair, computed tomography scans were obtained at 2 weeks and 1 year postoperatively.

RESULTS

Almost all outcome measures improved significantly in both groups. The percentage of sport resumption (PEMF, 79%; placebo, 80%; P = .95) and median time to sport resumption (PEMF, 17 weeks; placebo, 16 weeks; P = .69) did not differ significantly between the treatment groups. Likewise, there were no significant between-group differences with regard to the secondary functional outcomes and the computed tomography results.

CONCLUSION

PEMF does not lead to a higher percentage of patients who resume sports or to earlier resumption of sports after arthroscopic debridement and microfracture of talar OCDs. Furthermore, no differences were found in bone repair between groups.

REGISTRATION

Netherlands Trial Register NTR1636.

Lift, drill, fill and fix (LDFF): a new arthroscopic treatment for talar osteochondral defects

PURPOSE

The purpose of this study was to describe the short-term clinical outcome of a new arthroscopic fixation technique for primary osteochondral talar defects: lift, drill, fill and fix (LDFF).

METHODS

Seven patients underwent an arthroscopic LDFF surgery for osteochondral talar defects, the mean follow-up was 12 months (SD 0.6). Pre- and postoperative clinical assessment included the American Orthopaedic Foot and Ankle Society Score (AOFAS) and the numeric rating scales (NRS) of pain at rest and during walking. Remodelling and bone ingrowth after LDFF were analysed on weight-bearing radiographs during follow-up.

RESULTS

In all patients, LDFF led to an improvement of the AOFAS and NRS of pain. The AOFAS significantly improved from 63 to 99 (p < 0.001). The NRS of pain at rest significantly improved from 2.9 to 0.1 (p = 0.004), and pain with walking significantly improved from 7.6 to 0.1 (p < 0.001). On the final radiographs, five of seven patients showed remodelling and bone ingrowth after LDFF.

CONCLUSIONS

The LDFF of an osteochondral talar defect appears to be a promising arthroscopic treatment option for primary talar osteochondral defects. Although the clinical and radiological results of 1-year follow-up are encouraging, more patients and longer follow-up are needed to draw any firm conclusions and determine whether the results stand the test of time.

LEVEL OF EVIDENCE

Prospective case series. Therapeutic, Level IV.

The Mechanical Functionality of the EXO-L Ankle Brace: Assessment With a 3-Dimensional Computed Tomography Stress Test

BACKGROUND

A new type of ankle brace (EXO-L) has recently been introduced. It is designed to limit the motion of most sprains without limiting other motions and to overcome problems such as skin irritation associated with taping or poor fit in the sports shoe.

PURPOSE

To evaluate the claimed functionality of the new ankle brace in limiting only the motion of combined inversion and plantar flexion.

STUDY DESIGN

Controlled laboratory study.

METHODS

In 12 patients who received and used the new ankle brace, the mobility of the joints was measured with a highly accurate and objective in vivo 3-dimensional computed tomography (3D CT) stress test. Primary outcomes were the ranges of motion as expressed by helical axis rotations without and with the ankle brace between the following extreme positions: dorsiflexion to plantar flexion, and combined eversion and dorsiflexion to combined inversion and plantar flexion. Rotations were acquired for both talocrural and subtalar joints. A paired Student t test was performed to test the significance of the differences between the 2 conditions (P ≤ .05).

RESULTS

The use of the ankle brace significantly restricted the rotation of motion from combined eversion and dorsiflexion to combined inversion and plantar flexion in both the talocrural (P = .004) and subtalar joints (P < .001). No significant differences were found in both joints for the motion from dorsiflexion to plantar flexion.

CONCLUSION

The 3D CT stress test confirmed that under static and passive testing conditions, the new ankle brace limits the inversion-plantar flexion motion that is responsible for most ankle sprains without limiting plantar flexion or dorsiflexion.

CLINICAL RELEVANCE

This test demonstrated its use in the objective evaluation of braces.

Diagnosing, planning and evaluating osteochondral ankle defects with imaging modalities

This current concepts review outlines the role of different imaging modalities in the diagnosis, preoperative planning, and follow-up of osteochondral ankle defects. An osteochondral ankle defect involves the articular cartilage and subchondral bone (usually of the talus) and is mostly caused by an ankle supination trauma. Conventional radiographs are useful as an initial imaging tool in the diagnostic process, but have only moderate sensitivity for the detection of osteochondral defects. Computed tomography (CT) and magnetic resonance imaging (MRI) are more accurate imaging modalities. Recently, ultrasonography and single photon emission CT have been described for the evaluation of osteochondral talar defects. CT is the most valuable modality for assessing the exact location and size of bony lesions. Cartilage and subchondral bone damage can be visualized using MRI, but the defect size tends to be overestimated due to bone edema. CT with the ankle in full plantar flexion has been shown a reliable tool for preoperative planning of the surgical approach. Postoperative imaging is useful for objective assessment of repair tissue or degenerative changes of the ankle joint. Plain radiography, CT and MRI have been used in outcome studies, and different scoring systems are available.