Matthias Jacobi

Current Surgical Treatment of Knee Osteoarthritis

Osteoathritis (OA) of the knee is common, and the chances of suffering from OA increase with age. Its treatment should be initially nonoperative—and requires both pharmacological and nonpharmacological treatment modalities. If conservative therapy fails, surgery should be considered. Surgical treatments for knee OA include arthroscopy, cartilage repair, osteotomy, and knee arthroplasty. Determining which of these procedures is most appropriate depends on several factors, including the location, stage of OA, comorbidities on the one side and patients suffering on the other side. Arthroscopic lavage and débridement is often carried out, but does not alter disease progression. If OA is limited to one compartment, unicompartmental knee arthroplasty or unloading osteotomy can be considered. They are recommended in young and active patients in regard to the risks and limited durability of total knee replacement. Total arthroplasty of the knee is a common and safe method in the elderly patients with advanced knee OA. This paper summarizes current surgical treatment strategies for knee OA, with a focus on the latest developments, indications and level of evidence.

Association Between Mechanical Axis of the Leg and Osteochondritis Dissecans of the Knee Radiographic Study on 103 Knees

Background: The cause of osteochondritis dissecans (OCD) is unknown, but mechanical factors seem to play a role. Purpose: To identify a relationship between localization of OCD and mechanical axis of the leg. Study Design: Case series; Level of evidence, 4. Methods: Using bilateral full-leg standing radiographs, we analyzed the position of the mechanical axis of the leg in a group of 93 adolescent and adult patients (103 knees) with OCD of the medial or lateral femoral condyle. Results: The location of OCD and the position of the mechanical axis in the same knee compartment was significantly correlated for both knees with medial (P < .001) as well as lateral (P < .012) compartment OCD. In the medial OCD group, the mean mechanical axis was located in the medial knee compartment (28% medial ± 2.8%; range, 100% medial to 14% lateral) with a statistically insignificant medial shift with respect to the unaffected side. In lateral OCD, the mean mechanical axis was located laterally (13% lateral ± 3.9%; range, 13% medial to 60% lateral) with a significant shift from the medial into the lateral knee compartment when comparing unaffected with affected knees. No significant difference was observed between adolescents with open growth plates compared with adults with closed growth plates (P > .05). Conclusion: We found an association between medial condyle OCD and varus axis and between lateral condyle OCD and valgus axis. This evokes higher loading of the affected than of the unaffected knee compartment, and therefore, axial alignment may be a cofactor in OCD of the femoral condyles.

Avoiding intraoperative complications in open-wedge high tibial valgus osteotomy: technical advancement

Open-wedge high tibial osteotomy for varus osteoarthritis of the knee is a successful treatment option, but is associated with potential intraoperative complications, jeopardizing outcome. We describe four technical hints avoiding complications as tibia plateau fracture, lateral hinge dislocation, over- and undercorrection, and unwanted increase of the posterior tibial slope and axial malrotation. The technique, which is primarily based on placing five Kirschner-wires (one for the osteotomy direction, two for the external fixator, and two for rotational and slope control) is simple, reproducible, inexpensive, and readily available.

Patellar Tendon Tenodesis in Association With Tibial Tubercle Distalization for the Treatment of Episodic Patellar Dislocation With Patella Alta

Background: The association between patella alta and episodic patellar dislocation (EPD) has been well described, but its pathophysiology is not completely clear. Patella alta causes decreased contact between the patella and trochlea and decreased resistance to lateral translation of the patella. Additionally, increased patellar tendon length may allow pathologically increased coronal plane patellar motion. It may thus be desirable to address the length of the patellar tendon itself rather than just its insertion site. Hypothesis: Tenodesis of the patellar tendon in association with tibial tubercle distalization in patients with EPD and abnormally long patellar tendons (>52 mm) results in significant reduction in patellar tendon length, prevention of further patellar dislocation, and good knee function at long-term follow-up. Study Design: Case series; Level of evidence, 4. Methods: Twenty-seven knees in 22 patients with EPD and patella alta were treated with patellar tendon tenodesis and tibial tubercle distalization. Following tubercle distalization, the patellar tendon was tenodesed into the original location of the tibial tubercle with suture anchors. Changes in patellar tendon length and patellar height were measured radiographically. Any recurrent dislocation was documented, and patients completed an International Knee Documentation Committee (IKDC) subjective form at a mean of 9.6 years (range, 6-14 years) after surgery. Results: The mean length of the patellar tendon decreased from 56.3 ± 2.7 mm to 44.3 ± 8.6 mm (P < .0001). The Caton-Deschamps index decreased from 1.22 ± 0.17 to 0.95 ± 0.22 (P < .0001), and the Insall-Salvati ratio decreased from 1.42 ± 0.17 to 0.91 ± 0.18 (P < .0001). No patellar dislocations occurred postoperatively. The mean postoperative subjective IKDC score was 75.6 ± 9.5. Conclusion: Patellar tendon tenodesis and tibial tubercle distalization result in normalization of patellar tendon length, a stable patellofemoral joint, and good long-term knee function in patients with patella alta and EPD.

MACI - a new era?

Full thickness articular cartilage defects have limited regenerative potential and are a significant source of pain and loss of knee function. Numerous treatment options exist, each with their own advantages and drawbacks. The goal of this review is to provide an overview of the problem of cartilage injury, a brief description of current treatment options and outcomes, and a discussion of the current principles and technique of Matrix-induced Autologous Chondrocyte Implantation (MACI). While early results of MACI have been promising, there is currently insufficient comparative and long-term outcome data to demonstrate superiority of this technique over other methods for cartilage repair.

Reconstruction of the medial patellofemoral ligament using the adductor magnus tendon: an anatomic study.

PURPOSE The aims of this study were to evaluate the anatomic feasibility of medial patellofemoral ligament (MPFL) reconstruction using a part of the adductor magnus tendon and to identify possible risks. METHODS Twenty cadaveric knees were dissected. The distal part of the adductor magnus tendon was evaluated with respect to the anatomic topography and its utility for MPFL reconstruction. To estimate the risk of injuring the neurovascular structures, the distance from the adductor tubercle to the adductor hiatus was evaluated. An MPFL reconstruction was carried out by preserving the distal insertion on the adductor tubercle and redirecting the proximal portion of the tendon to the medial aspect of the patella. RESULTS The anatomic investigation showed the following relationships: The mean distance from the adductor tubercle to the adductor hiatus was 99 ± 14 mm (range, 80 to 120 mm). A graft length of 52 ± 5 mm (range, 45 to 63 mm) with the addition of 10 to 20 mm for fixation was found to be necessary for MPFL reconstruction. The difference between the desired graft length and the distance to the adductor hiatus was found to be at least 30 mm in all cases (mean, 46 mm). Leaving the graft attached to the adductor tubercle resulted in a nearly anatomic femoral attachment of the reconstructed MPFL. Complete detachment of the distal adductor magnus attachment was consistently avoidable. CONCLUSIONS The adductor magnus tendon was found to be a useful graft for MPFL reconstruction. However, anatomic dangers (damage to the neurovascular bundle of the adductor hiatus, the saphenous nerve, or the saphenous branch of the descending genicular artery) during graft harvest must be considered. CLINICAL RELEVANCE Anatomic knowledge is essential during adductor magnus tendon harvest to avoid damage to neurovascular structures. The adductor magnus tendon is an interesting alternative graft option for MPFL reconstruction if anatomic dangers are considered and avoided.

Systemic exposure to tobramycin after local antibiotic treatment with calcium sulphate as carrier material

IntroductionOsteoset® T is a calcium sulphate void filler containing 4% tobramycin sulphate, used to treat bone and soft tissue infections. Despite systemic exposure to the antibiotic, there are no pharmacokinetic studies in humans published so far. Based on the observations made in our patients, a model predicting tobramycin serum levels and evaluating their toxicity potential is presented.MethodsFollowing implantation of Osteoset® T, tobramycin serum concentrations were monitored systematically. A pharmacokinetic analysis was performed using a non-linear mixed effects model based on a one compartment model with first-degree absorption.ResultsData from 12 patients treated between October 2006 and March 2008 were analysed. Concentration profiles were consistent with the first-order slow release and single-compartment kinetics, whilst showing important variability. Predicted tobramycin serum concentrations depended clearly on both implanted drug amount and renal function.Discussion and conclusionDespite the popularity of aminoglycosides for local antibiotic therapy, pharmacokinetic data for this indication are scarce, and not available for calcium sulphate as carrier material. Systemic exposure to tobramycin after implantation of Osteoset® T appears reassuring regarding toxicity potential, except in case of markedly impaired renal function. We recommend in adapting the dosage to the estimated creatinine clearance rather than solely to the patient’s weight.

Lateral Extra-articular Augmentation of ACL Reconstruction

Reconstruction of the anterior cruciate ligament (ACL) is a common orthopedic procedure. It has been suggested that a single-bundle reconstruction does not completely control tibial anterior translation and rotation in all cases. Several techniques have been described to improve stability, including double-bundle intra-articular reconstruction and lateral extra-articular augmentation. Extra-articular augmentation has been suggested in patients with significant anterolateral rotatory instability, cases of revision ACL reconstruction, and when one wishes to protect the ACL graft from excess force such as in collision athletes. It is contraindicated for patients with posterolateral corner injuries and for the skeletally immature patients. The procedure described in this report uses a patellar tendon autograft for the intra-articular portion and a gracilis autograft for the extra-articular augmentation. Fixation of the gracilis tendon is achieved by a press-fit technique on the femur and through a drill hole in Gerdy tubercle on the tibia. Reported outcomes are variable, but lateral augmentation has been shown in some series to control rotational instability more effectively than isolated single-bundle or double-bundle intra-articular reconstruction. More work is required to completely define the indications.

Repositioning and stabilization of the radial styloid process in comminuted fractures of the distal radius using a single approach: the radio-volar double plating technique

BackgroundA possible difficulty in intra-articular fracture of the distal radius is the displacement tendency of the radial styloid process due to the tension of the brachioradialis tendon.MethodsTen patients treated within one year for complex distal radius fractures by double-plating technique with a radial buttress plate and volar locking plate, through a single volar approach, were followed prospectively during 24 months. Outcome measures included radiographic follow-up, range of motion, grip strength and score follow-up (VAS, Gartland-Werley score and patient-rated wrist evaluation).ResultsTen patients with intraarticular distal radius fractures with dislocation of the radial styloid process were treated with this technique. This resulted after 24 months in good clinical outcome (mean visual analog scale 0.9; almost symmetric range of motion; mean Gartland-Werley score 2 ± 3; mean patient-rated wrist evaluation 3.2 ± 2.4). Radiologic evaluation according to the Dresdner Score revealed anatomic reduction without secondary dislocation during the follow-up and uneventful consolidation.ConclusionsThe described technique strongly facilitates anatomic reduction and stable fixation of intra-articular distal radius fractures with dislocation of the radial styloid process and leads to satisfactory clinical and radiographic outcome.

The concept of double bundle ACL simulation with a single bundle patellar tendon graft. A cadaveric feasibility study

BackgroundThere is significant interest in the restoration of the double-bundle anatomy of the native ACL when performing ACL reconstruction. Possible techniques include those utilizing two separate grafts with independent tunnels and those that attempt to mimic this anatomy with a single graft and fewer tunnels. Many of the latter techniques require specific instrumentation and are technically challenging. We demonstrate that the double-bundle anatomy of the native ACL can theoretically be mimicked by a single-bundle reconstruction.MethodsWe performed single bundle ACL reconstruction with a bone-patellar tendon-bone (BTB) graft in two cadaveric knees. Both grafts were placed to mimic the native ACL footprints – one reconstruction was performed with rectangular bone blocks and oval tunnels and one was performed utilizing a standard BTB graft and round tunnels. Qualitative assessment of graft behavior was made as the knees were taken through a range of motion.ResultsThe ACL graft was able to qualitatively mimic the behavior of the native ACL in both knees provided the bone blocks were correctly orientated.ConclusionsACL reconstruction with a single BTB graft can qualitatively mimic the behavior of the two bundles of the native ACL. The key to ensuring this behavior was noted to be appropriate orientation of the graft in the tunnels. Quantitative biomechanical investigations are necessary to evaluate the impact of graft orientation on function.