Fixation stability following high tibial osteotomy: a radiostereometric analysis

A systematic approach to managing complications after proximal tibial osteotomies of the knee

Proximal tibial osteotomy (PTO) is an effective procedure for active and young adult patients with symptomatic unicompartmental osteoarthritis and malalignment. They were considered technically demanding and prone to various complications related to the surgical technique, biomechanical or biological origin. Among the most important are hinge fractures and delayed or non-healing, neurovascular complications, loss of correction, implant-related problems, patellofemoral complaints, biological complications and changes in limb length. Being aware of these problems can help minimizing their prevalence and improve the results of the procedure.The aim of this narrative review is to discuss the potential complications that may occur during and after proximal tibial osteotomies, their origin and ways to prevent them.

Dome-shaped high tibial osteotomy with semi-circular Ilizarov pin fixator: Mid- to long-term results of a novel technique

BACKGROUND

The aim of this study was to assess the clinical and radiological results of the dome-shaped high tibial osteotomy (HTO) which was fixed with a novel construct comprised of semi-circular Ilizarov frames and pins.

METHODS

The patients with at least five years of follow-up were evaluated. One-hundred and thirty-two knees of 114 patients were included in the final analysis. The clinical evaluation included range of motion and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score. Anatomical femorotibial angle (aFTA), anatomical medial proximal tibial angle (aMPTA), tibial slope and Insall-Salvati ratio were calculated on standard weight-bearing radiographs.

RESULTS

The average aFTA was improved from 1.6° varus to 8.7° valgus (P < 0.001). The average WOMAC score (P < 0.001) and flexion value (P = 0.014) were improved at the latest follow-up (WOMAC: 17.2, flexion: 142.5) compared with the preoperative period (WOMAC: 59.6, flexion: 129.2). The sagittal radiological parameters were not significantly affected. The five-year survival was 96.2%, and 10-year survival was 83.3%.

CONCLUSIONS

The semi-circular Ilizarov pin construct provided satisfactory outcomes both clinically and radiologically at mid- to long-term follow-up.

Advances in modern osteotomies around the knee : Report on the Association of Sports Traumatology, Arthroscopy, Orthopaedic surgery, Rehabilitation (ASTAOR) Moscow International Osteotomy Congress 2017

Corrective lower limb osteotomies are innovative and efficient therapeutic procedures for restoring axial alignment and managing unicompartmental knee osteoarthritis. This review presents critical insights into the up-dated clinical knowledge on osteotomies for complex posttraumatic or congenital lower limb deformities with a focus on high tibial osteotomies, including a comprehensive overview of basic principles of osteotomy planning, biomechanical considerations of different implants for osteotomies and insights in specific bone deformity correction techniques. Emphasis is placed on complex cases of lower limb osteotomies associated with ligament and multiaxial instability including pediatric cases, computer-assisted navigation, external fixation for long bone deformity correction and return to sport after such osteotomies. Altogether, these advances in the experimental and clinical knowledge of complex lower limb osteotomies allow generating improved, adapted therapeutic regimens to treat congenital and acquired lower limb deformities.

RSA in Spine: A Review

STUDY DESIGN

Systematic review of literature.

OBJECTIVES

This systematic review was conducted to investigate the accuracy of radiostereometric analysis (RSA), its assessment of spinal motion and disorders, and to investigate the limitations of this technique in spine assessment.

METHODS

Systematic review in all current literature to invesigate the role of RSA in spine.

RESULTS

The results of this review concluded that RSA is a very powerful tool to detect small changes between 2 rigid bodies such as a vertebral segment. The technique is described for animal and human studies for cervical and lumbar spine and can be used to analyze range of motion, inducible displacement, and fusion of segments. However, there are a few disadvantages with the technique; RSA percutaneous procedure needs to be performed to implant the markers (and cannot be used preoperatively), one needs a specific knowledge to handle data and interpret the results, and is relatively time consuming and expensive.

CONCLUSIONS

RSA should be looked at as a very powerful research instrument and there are many questions suitable for RSA studies.

RSA Applications in Monitoring of Fracture Healing in Clinical Trials

Radiostereometric analysis (RSA) was originally developed as a method for performing highly accurate three-dimensional measurements in vivo over time from sequential radiographs. Since its introduction over twenty years ago, the RSA method has proven itself as a powerful tool with numerous orthopaedic applications. RSA has been used extensively in studies of prosthetic fixation and has been shown to be the method of choice for these studies. RSA has, however, also been successfully applied to a limited number of studies examining fracture healing, namely in fractures of the radius, ankle, tibial plateau, trochanter and femoral neck, as well as studies of bone healing following spinal fusion and tibial osteotomies. RSA follow-up of a fracture will provide definitive demonstration of the exact time of union, i.e. the achievement of fracture stability. This information can be invaluable in randomized clinical trials of fracture treatment. Phantom model studies have proven useful for effective preoperative planning and interpretation of RSA results. The RSA method is a highly accurate, precise and safe objective method for studying fracture healing in clinical trials. The RSA method may serve as a scientific tool to accurately evaluate the significance of supporting novel biomaterials for the early stability and the rate of healing in fractures.

Radiostereometric analysis of early anatomical changes following medial opening wedge high tibial osteotomy

BACKGROUND

The objective of this study was to use radiostereometric analysis (RSA) to evaluate the anatomical changes that occur in the tibia immediately after surgical correction with medial opening wedge high tibial osteotomy (HTO), and the changes that occur over the course of the first twelveweeks of osseous union.

METHODS

Patients included nine males and one female, with a mean age of 49.0 ± 5.5 years and mean BMI of 28.4 ± 3.8 kg/m(2). The patients underwent HTO using a non-locking plate. RSA marker beads were inserted in the tibia, femur, and patella. RSA exams were first obtained intra-operatively prior to the osteotomy, and subsequently at one, two, four, six, and twelveweeks postoperatively.

RESULTS

Patients were corrected from a mean alignment preoperatively of 8.6 ± 2.5° to 0.3 ± 1.9° postoperatively, with a mean osteotomy of 12.5 ± 3.6mm. Immediate tibia changes surrounding the osteotomy site included 9.2 ± 2.4° of valgus rotation and 6.2 ± 2.0mm of distal translation. Secondary motions included 2.5 ± 2.4° of internal rotation of the distal tibia, 1.8 ± 1.4mm of posterior movement of the femur, and 8.5 ± 3.4mm of patella baja. Micromotion between the proximal and distal tibial segments decreased over time.

CONCLUSION

The results suggest that subtle changes to the anatomy occur, beyond what is intended with the procedure, but partial corrections of these phenomena occurred over the twelveweeks. Micromotion surrounding the osteotomy site decreased with osseous union.

Differences in fixation stability between spacer plate and plate fixator following high tibial osteotomy

PURPOSE

Since in vivo stability following high tibial osteotomy is unknown, surgeons customize the postoperative rehabilitation to the assumed implant stability, leaving us with numerous rehabilitation protocols. The purpose of the study is to quantify the fixation stability of different open-wedge high tibial osteotomy implants. It is hypothesized that the higher fixation stability of a plate fixator justifies early weight bearing.

METHODS

In this prospective 30-subject clinical trial, fixation stability was determined over a 2-year period using radiostereometric analysis (RSA). Patients were assigned to two angle-stable osteotomy plates: a spacer plate with 6 postoperative weeks of feather-touch weight bearing versus a plate fixator with 2 postoperative weeks of feather-touch weight bearing.

RESULTS

Postoperative RSA data showed a significant higher lateral translation of the distal tibia and a significantly increased subsidence, varus and internal rotation of the tibial head in the spacer plate compared to the plate fixator group. Weight bearing following spacer plate fixation induced significant micromotion 6 weeks after surgery. Three months after surgery, bone healing was achieved regardless of the used implant.

CONCLUSIONS

Early weight bearing is appropriate for plate fixator fixation. The 6-week period of delayed weight bearing following spacer plate fixation is inadequate and should be prolonged presumably up to 8-10 weeks to avoid pseudarthrosis and/or recurrence of varus angulation.

LEVEL OF EVIDENCE

Level II, diagnostic study--investigating a diagnostic test.

High tibial osteotomy for the treatment of unicompartmental knee osteoarthritis: a review of the literature, indications, and technique

In the past decades, there has been varying support for high tibial osteotomy. This surgical procedure was originally popularized by Mark B. Coventry, MD in the 1960s, but fell out of favor with orthopedic surgeons as knee arthroplasty became more commonplace. In the past 10 years, osteotomy has been rediscovered as an important adjunct to cartilage repair procedures that rely on a normalized biomechanical environment. Furthermore, there has been an increase in the number of patients presenting with unicompartmental disease (eg, after prior meniscectomy) who are at an age and functional level that is not ideally suited for joint arthroplasty. High tibial osteotomy allows 70% to 85% of patients to delay arthroplasty for ≥ 5 to 10 years and 50% to 60% for ≥ 15 years. This article provides an overview of the indications, technique, complications, and outcomes of high tibial osteotomy, specifically the more commonly used opening wedge technique.

Three-dimensional evaluation of the cyclic loading behavior of different rotator cuff reconstructions

PURPOSE

To perform a biomechanical comparison of single-row rotator cuff repairs with modified suture configurations versus double-row repairs using radiostereometric analysis (RSA).

METHODS

The infraspinatus tendon and the humerus of 40 porcine cadaveric shoulders were marked with tantalum beads and placed in an RSA calibration cage that allows for calculation of 3-dimensional positions of the tantalum markers. The intact tendon was cyclically loaded (50 cycles/20 N). After sharp dissection of the infraspinatus from the bone, the repairs were made by use of 3 single-row (modified Mason-Allen, double mattress, inclined mattress) and 2 double-row (modified Mason-Allen, suture bridge) configurations. The reconstructions were cyclically loaded for 50 cycles (10 N to 40, 60, 80, and 100 N). Displacements under cyclic loading were quantified in the anteroposterior (x), craniocaudal (y), and mediolateral (z) direction. The craniocaudal measurements were compared with the results of a video extensometer.

RESULTS

Cyclic loading of the intact tendon showed a mean displacement of 0.06 +/- 0.08 mm at the x-level, 0.16 +/- 0.18 mm at the y-level, and 0.19 +/- 0.28 mm at the z-level. High correlations between the RSA and the video extensometer measurements were found (0.87). Comparison of rotator cuff repairs showed significant differences in gap formation at 40, 60, 80, and 100 N in the craniocaudal plane (P < .0001) and the mediolateral plane (P <or= .05), with the double-row Mason-Allen repair providing the lowest gap formation of all tested configurations. However, these results were not statistically significant compared with the single-row double-mattress repair. No significant differences were measured at the anteroposterior level (P > .05).

CONCLUSIONS

Single-row repairs using modified Mason-Allen or double-mattress repair were able to achieve biomechanical results comparable to double-row repairs as measured by RSA and digital video.

CLINICAL RELEVANCE

Single-row repairs, using modified suture configurations, were able to decrease implant costs compared with double-row repairs, by achieving comparable results. Furthermore, RSA gives additional information on the applied forces acting on the rotator cuff repair in 3 different planes, which may help to decrease the rerupture rate of rotator cuff reconstructions.

Osteotomies about the knee for tibiofemoral malalignment in the athletic patient

Osteotomies have a role in the active patient with degenerative joint disease of the medial or lateral knee who, for reasons of age or activity level, is not yet a good candidate for prosthetic arthroplasty. Recognition and treatment of malalignment associated with ligamentous instability is essential if long-term good outcomes are to be expected from ligamentous reconstruction. Also, treatment of concomitant malalignment and the unloading of the operative site is now recognized as an important adjunct to any cartilage-preserving surgery. This review examines the use of osteotomies about the knee in the athletic patient. Indications, contraindications, preoperative planning, surgical techniques, and complications are reviewed.

Effect of a biplanar osteotomy on primary stability following high tibial osteotomy: a biomechanical cadaver study

Open-wedge high tibial osteotomy (HTO) is becoming increasingly popular for the treatment of varus gonarthrosis in the active patient. The various implants used in HTO differ with regard to its design, the fixation stability and osteotomy technique. It is assumed that the combination of a plate fixator with a biplanar, v-shaped osteotomy supports bone healing. So far, there are no biomechanical studies that quantify the stabilizing effect of a biplanar versus uniplanar osteotomy. We hypothesized that a significant increase in primary stability of bone-implant constructs is achieved when using a biplanar as opposed to a uniplanar osteotomy. Twenty-four fresh-frozen human tibiae were mounted in a metal cylinder, and open-wedge osteotomy (12 mm wedge size) was performed in a standardized fashion. Proximal and distal tibial segments were marked with tantalum markers of 0.8 mm diameter. Two different plates with locking screws were used for fixation: a short spacer plate (group 1, n = 12) and a plate fixator (group 2, n = 12). In six specimens of each group, a biplanar V-shaped osteotomy with a 110 degrees angulated anterior cut behind the tuberosity parallel to the ventral tibial shaft axis was performed. In the remaining six specimens of each group, a simple uniplanar osteotomy was performed in an oblique fashion. Axial compression of the tibiae was performed using a material testing machine under standardized alignment of the loading axis. Load-controlled cyclical staircase loading tests were performed. The specimens were radiographed simultaneously in two planes together with a biplanar calibration cage in front of a film plane with and without load after each subcycle. Radiostereometry allowed for serial quantification of plastic and elastic micromotion at the osteotomy site reflecting the stability provided by the combination of implant and osteotomy technique. No significant additional stabilizing effect of a biplanar osteotomy in craniocaudal and mediolateral plane was found. However, additional stability was achieved in anteroposterior (AP) and all rotational planes in those specimens fixated with a short spacer plate. In this biomechanical set-up with axial load, the additional stabilizing effect of a biplanar osteotomy did not come into effect in the presence of a long and rigid plate fixator. However, biplanar osteotomy increased the fixation stability significantly in AP and rotational planes when a short spacer plate was used. Clinically, the biplanar osteotomy promotes bone healing regardless of the implant used. Biomechanically, biplanar osteotomy is advantageous for shorter plate designs to increase primary stability of the bone-implant construct.

Differentially loaded radiostereometric analysis to monitor fracture stiffness: a feasibility study

Inability to accurately and objectively assess the mechanical properties of healing fractures in vivo hampers clinical fracture management and research. We describe a method to monitor fracture stiffness during healing in a clinical research setting by detecting changes in fracture displacement using radiostereometric analysis and simultaneously measuring applied axial loads. A method was developed for load application, positioning of the patient, and radiographic setup to establish the technique of differentially loaded radiostereometric analysis (DLRSA). A DLRSA examination consists of radiostereometric analysis radiographs taken without load (preload), under different increments of load, and without load (postload). Six patients with distal femur fractures had DLRSA examinations at 6, 12, 18, and 26 weeks postoperatively. The DLRSA method was feasible in a clinical setting. The method provides objective and quantifiable data for internally fixed fractures and may be used in clinical research as a tool to monitor the in vivo stiffness of healing femoral fractures managed with nonrigid internal fixation.

Physeal sparing arthroscopic fixation of displaced tibial eminence fractures: a new surgical technique

We describe a novel physeal sparing arthroscopic technique for anatomic suture refixation of tibial eminence fractures and assess the mid-term results of six consecutive patients (McKeever type II n = 2, III n = 3 and IV n = 1). The mean follow-up was 5 +/- 2 years. Five of six patients were painfree. All patients returned to their preinjury sport level. Mean passive ipsilateral and contralateral flexion was 143 degrees +/- 5 degrees. The IKDC score was A in five and B in one patients. The mean Lysholm score was 97 +/- 3%. The median Tegner score was 8 (range 6-9) preinjury and at follow-up. The mean Total Knee Society score was 197 +/- 4 points. ACL laxity (KT-1000 134 N) showed a side-to-side difference of 2 +/- 2 mm. Two of six patients underwent a tibial screw removal under local anaesthesia. No loss of reduction or grossly physeal disturbance was observed. The reported surgical technique showed excellent to good clinical and radiological results and may be a physeal sparing alternative to previously described procedures.