Christian Plaass

Anterior double plating for rigid fixation of isolated tibiotalar arthrodesis.

Background: Arthrodesis is the most common procedure used to treat end-stage osteoarthritis of the ankle, particularly in patients with difficult conditions such as poor bone quality. While many techniques are available to fuse the ankle, current recommendations favor the use of internal fixation with screws and/or plates. Despite of progress, the complication rate remains a major concern. Non-union is one difficult problem especially with difficult bone conditions, particularly the loss of bone stock on the talar side. Therefore, fusion of the tibiotalar joint is often extended to the talocalcaneal joint to provide sufficient stability. To preserve the subtalar joint, an anterior double plate system for rigid fixation of isolated tibiotalar arthrodesis was developed. This is a preliminary report on the clinical and radiological outcome with this technique. Materials and Methods: Twenty-nine patients (15 men, 14 women; one ankle per patient) were treated from October 2006 to September 2007. We converted 16 ankles with osteoarthritis and difficult bone conditions, four non-united ankle arthrodeses, and nine failed total ankle replacements to an isolated tibiotalar arthrodesis using anterior double plating. If necessary, we used solid allograft to fill bony defects. Outcomes included bone union as assessed by radiographs, pain as indicated by the American Orthopaedic Foot and Ankle Society scores, and patient satisfaction. Results: Solid arthrodesis was achieved after an average of 12.3 (eight to 26) weeks in the 16 ankles without bone graft interposed between the tibia and talus, and 14.3 (range, 8 to 26) weeks in the 13 ankles with interpositional bone allograft. Radiographs showed that the position of arthrodesis obtained at the time of surgery did not change in any patient up to one year after surgery. The mean American Orthopaedic Foot and Ankle Society (AOFAS) Hindfoot Score increased from 37 (range, 20 to 63) preoperatively to 68 (range, 50 to 92) at the last followup. Twenty-seven patients (93%) were satisfied with their outcome and indicated they would have the operation again. No complications were noted. Conclusion: The anterior double plating system was shown be a reliable method to achieve solid isolated tibiotalar arthrodesis, even in ankles with difficult conditions such as loss of bone stock due to failed total ankle arthroplasty. Level of Evidence: IV, Retrospective Case Series

Influence of leg length discrepancy on clinical results after total hip arthroplasty - A prospective clinical trial

The effect of leg length differences on early clinical outcome after total hip arthroplasty remains uncertain. We performed a prospective study on 94 patients who were evaluated preoperatively and one year after surgery for clinical leg length differences, which were then compared with radiological measurements. The effect of leg length differences on walking ability, limp, pain and patient satisfaction was studied. The mean clinical leg length difference after operation was 0.05 cm (–1.5 to 1.5, SD 0.5). Clinical and radiological measurements correlated poorly (ω=0.36 pre- and ω=0.186 postoperatively). Patients with a shorter operated leg on clinical assessment were more prone to limping (p<0.05), and patients with a longer leg had more pain compared to patients with equal leg lengths (p<0.05). Walking ability, Harris Hip Score and patient satisfaction were only marginally affected by leg length differences. Virtually equal leg length was achieved for most patients but small differences had a negative influence in relation to limping and pain. Patients should be counselled pre-operatively about possible leg length differences and associated symptoms.

Early results using a biodegradable magnesium screw for modified chevron osteotomies: MG SHORT TERM

This is the first larger study analyzing the use of magnesium‐based screws for fixation of modified Chevron osteotomies in hallux valgus surgery. Forty‐four patients (45 feet) were included in this prospective study. A modified Chevron osteotomy was performed on every patient and a magnesium screw used for fixation. The mean clinical follow up was 21.4 weeks. The mean age of the patients was 45.5 years. Forty patients could be provided with the implant, in four patients the surgeon decided to change to a standard metallic implant. The AOFAS, FAAM and pain NRS‐scale improved markedly. The hallux valgus angle, intermetatarsal angle and sesamoid position improved significantly. Seven patients showed dorsal subluxation, rotation or medial shifting of the metatarsal heads within the first 3 months. One of these patients was revised, in all others the findings were considered clinically not significant or the patients refused revision. This study shows the feasibility of using magnesium screws in hallux valgus‐surgery. Surgeons starting with the use of these implants should be aware of the proper handling of these implants and should know about corrosion effects during healing and its radiographic appearance.

Anatomical variations of the flexor hallucis longus and flexor digitorum longus in the chiasma plantare.

Background: The flexor hallucis longus (FHL) and flexor digitorum longus (FDL) tendon are routinely used in reconstructive foot and ankle surgery. The tendons cross in the chiasma plantare and show variable interconnections. This can complicate harvesting of the tendons. Previous anatomical studies were inconclusive and did not reference the connections to surgically relevant landmarks. The purpose of this study was to integrate these conflicting results, introduce a thorough classification system, and analyze the position of the interconnections relative to the surgically relevant bone landmarks. Methods: Sixty embalmed feet of 30 cadavers were analyzed anatomically with respect to the individual cross-links in the planta pedis. All feet were photo documented. The interconnections were classified in a modified classification system and distances to surgically relevant anatomic landmarks measured. Results: A proximal to distal connection from the FHL to the FDL was found in 95% of the feet (types I and III), in 3% there was a proximal to distal connection from the FDL to the FHL (type II) tendon only, and in 30% a crossed connection (type III) was found. The average point of branching of the FHL and FDL tendon was 5.3 and 4.6 cm distal to the medial malleolus, respectively. Conclusion: Our modified classification system accommodated all found variations. In over 90% of the feet, a proximal to distal connection from the FHL to the FDL was found, which might contribute to the residual function of the lesser toes after FDL transfer. Clinical Relevance: The exact knowledge of the anatomy of the crossing of FDL and FHL in the plantar foot is essential to facilitate tendon harvesting, reduce morbidity and explain possible postoperative functional loss.

Influence on Therapeutic Decision Making of SPECT-CT for Different Regions of the Foot and Ankle

Background. Single-photon emission computed tomography and computed tomography (SPECT-CT) has a high impact on diagnosis and treatment decision of different joints. The aim of this study was to evaluate whether there is a different gain of SPECT-CT for different foot regions. Material and Methods. We retrospectively identified 86 patients who received a SPECT-CT of the foot and ankle between April 2011 and December 2012. We divided all patients into the following subgroups: ankle (group 1), subtalar (group 2), Chopart (group 3), and Lisfranc (group 4). The local ethical committee approved the study. Results. The clinical treatment decision was changed based on SPECT-CT results in 64.5% of group 1, 65.2% of group 2, and 75% each of groups 3 and 4. Eighty patients (93%) had pain relief after treatment based on SPECT-CT. The overall SPECT-CT sensitivity was 0.94 and the specificity was 0.57. The positive and negative predictive values were 0.87 and 0.75, respectively. Conclusion. The impact of SPECT-CT on treatment decision is slightly higher in diseases of the Chopart and Lisfranc joints than in the upper ankle and subtalar joints. The additional information has a clinical relevance due to the high rate of pain relief by treatment based on SPECT-CT diagnosis.

Operative Treatment of the Insertional Achilles Tendinopathy Through a Transtendinous Approach.

Background: Different operative techniques have been proposed for the treatment of insertional Achilles tendinopathy (IAT), with often disappointing results. The aim of this study was to evaluate the outcome of the transtendinous approach in IAT. Methods: Forty patients operated with an IAT between 2010 and 2011 were included in this retrospective study. The mean follow-up was 15.6 (±3.7, 12-27) months. Indication for surgery was IAT with failed conservative therapy. Using a transtendinous approach, the Achilles tendon (AT) was partially detached and all pathologic tissues were debrided. The AT was reinserted using different anchor techniques. Clinical data were recorded using examination and clinical scores (American Orthopaedic Foot & Ankle Society [AOFAS], Foot and Ankle Outcome Score [FAOS], Numerical Rating Scale [NRS], and Short Form-36 [SF-36]). Results: The mean AOFAS hindfoot score improved from 59.4 preoperatively to 86.5 postoperatively (P < .05). All FAOS subscales, NRS pain scores, and pain and function subscales of SF-36 improved significantly. The median time of return to work and sports was 14.5 (±17.6; 2-82) and 22.7 (±13.4; 7-58) weeks. Three patients had superficial wound healing difficulties but required no revision. One patient had to be revised due to a hematoma. Patients treated with 2 suture anchors or double-row fixation technique improved significantly (P < .05) compared to those with single anchor fixation, regarding AOFAS score (79.6 and 90.2) and FAOS subscale scores. Eighty-three percent of the patients showed good to excellent results. Conclusion: The transtendinous approach allowed access to all associated pathologies in IAT. It had relatively few complications and lead to good clinical results. Level of Clinical Evidence: Level IV, retrospective case series.

Placement of Plantar Plates for Lapidus Arthrodesis Anatomical Considerations

Background: The modified Lapidus procedure is an accepted treatment option for patients with moderate to severe hallux valgus. Placing a plate plantar on the tension side of the arthrodesis has been shown to be biomechanically superior and has provided good clinical results. There is some concern about interference of the plantar placed plates on the tendon insertions. The purpose of this study was to determine a “safe zone” for plantar plate placement without irritation of the tendons. Methods: Twenty-nine embalmed right feet were used for this study. The anatomy of the insertion of the peroneus longus (PL) tendon and tibialis anterior (TA) tendon on the medial cuneiform and first metatarsal were analyzed. Six different plate designs for plantar plating of the first tarsometatarsal fusion were included. The fit to the bone and contact to tendon insertion were analyzed. Results: The PL showed a main insertion to the first metatarsal and a lesser insertion to the medial cuneiform. The TA inserted onto the medial cuneiform and first metatarsal in all cases in our series. There was a “safe zone” between the TA and PL insertion areas for plate placement. Straight, Y- and U-shaped plates could be placed without compromising the tendon insertion. Depending on the design, even preshaped plates may have to be bent to allow a good fit to the plantar side of the first tarsometatarsal joint. Conclusion: Plantar plating for modified Lapidus arthrodesis can be safely performed, without damaging the plantar tendon insertion area of the PL and TA. Clinical Relevance: The exact knowledge of the anatomy of the plantar region of the tarsometatarsal joint can help to improve plate placement.

Role of MRI in Detection of Morton’s Neuroma

Background: Distinguishing between patients with a true Morton’s neuroma and other forefoot pathology can be difficult. The aim of this study was to evaluate the diagnostic accuracy of routine magnetic resonance imaging (MRI) when compared to clinical examination for Morton’s neuroma. Methods: We retrospectively identified 71 patients who underwent operative treatment due to the diagnosis of Morton’s neuroma between 2007 and 2013. All patients had a MRI preoperative. Our study group comprised 58 female and 13 male patients with a mean age of 57 (range, 38-92) years. We compared the results of preoperative MRI and the patient’s clinical assessment with postoperative histopathological results. Results: Typical clinical signs were found in 65 cases. Most common symptoms were plantar pain (92%) and increased pain on walking (89%). A Morton’s neuroma was detected on MRI in 59 of 71 cases. Its sensitivity was 0.84 and its specificity was 0.33. The positive and negative predictive values were 0.97 and 0.08, respectively. For the presence of main clinical symptoms we found a sensitivity of 0.94 and a specificity of 0.33. The positive predictive value was 0.97 and the negative predictive value was 0.20. Conclusion: MRI under routine conditions had a good detection rate for the evaluation of Morton’s neuroma. However, its accuracy was not as high as the accuracy of clinical assessment. Level of Evidence: Level IV, retrospective series.

Two-Stage Revision Total Knee Arthroplasty in Cases of Periprosthetic Joint Infection: An Analysis of 50 Cases

Objectives: A periprosthetic joint infection (PJI) is a significant complication after total knee arthroplasty (TKA). Still there is no agreement on a perfect diagnosis and treatment algorithm. The aim of this study was to evaluate the success and revision rates after two-stage revision total knee arthroplasty (TKA) and factors that affect the success rate. Material and Methods: 50 consecutive two-stage revision TKAs were performed between January 2011 and December 2012. We retrospectively reviewed study patients charts including demographics, prior surgeries, comorbidities, incidence of persistent infection and revisions. At the final follow-up examination the patients satisfaction, pain level and disorders were evaluated. A successful clinical outcome was defined as a functioning prosthesis without wound healing disorders, no sinuses tracts or other clinical evidence of a persistent infection. Results : Re-implantation of prosthesis was performed in 47 cases; three patients received a septic arthrodesis. Twelve patients had a persistent infection despite two-stage re-implantation resulting in a success rate of 76.0%. In eight of these twelve patients an infecting germ was isolated during second-stage procedure. Three patients received another two-stage revision arthroplasty and one patient an above knee amputation. A revision was performed in 23 of 50 patients (46.0%). Factors that diminish the success rate were further operations after primary TKA (p = 0.048), prior revision arthroplasties after TKA (p = 0.045), nicotine abuse (p = 0.048), Charlson comorbidity index above a score of 2 (p = 0.031) and a mixed flora during first-stage procedure (p < 0.001). Age, sex, immune status, chronic anticoagulant use, rheumatoid arthritis, body mass index and the presence of multidrug resistant germs showed no significant effect on success rate (p > 0.05). Conclusion : We found that patients who required surgery after the primary TKA, had a higher Charlson comorbidity index or were found to have mixed flora during explantation. The treatment of PJI remains difficult, both for the patient and for the treating surgeons.

Preoperative diagnostic for periprosthetic joint infection prior to total knee revision arthroplasty

Periprosthetic joint infection (PJI) after total knee arthroplasty remains a challenging problem. The aim of this study was to evaluate the accuracy of diagnostic knee aspiration and serum inflammatory markers in diagnostic of a PJI after total knee arthroplasty. Within 2011 and 2012, 46 patients received a one- or two-stage revision arthroplasty of the knee joint. These patients received a total number of 77 operations. A preoperative aspiration was performed in each case. We analyzed the microbiological and histological examinations of the samples from the aspiration and from the revision operation and additionally estimated serum inflammatory markers. The diagnostic aspiration had a specificity of 0.87, a sensitivity of 0.39, a positive predictive value of 0.67 and a negative predictive value of 0.68. For C-reactive protein the specificity was 0.61 and the sensitivity was 0.48, the serum white blood cell count had a specificity of 0.98 and a sensitivity of 0.23. Our data queries whether diagnostic joint aspiration or serum inflammatory markers are sufficient to verify or exclude a PJI.