Pulsatile Lavage Improves Tibial Cement Penetration and Implant Stability in Medial Unicompartmental Arthroplasty: A Cadaveric Study.

Cemented unicompartmental knee arthroplasty (UKA) shows good survivorship and function. However, implant failure, causing the need for revision, can occur. Aseptic loosening is still among the most common reasons for revision. The purpose of this study was to assess the influence of preimplantation lavage technique on tibial cement penetration depth, tibial cement volume, and load to fracture in the tibial component of mobile-bearing UKA. In 10 pairs of fresh frozen human tibiae, cemented UKA was implanted by an experienced surgeon. Tibial components were then implanted, left and right tibiae were randomly allocated to group A or B. Prior to implantation, irrigation was performed with either syringe lavage or pulsatile jet lavage in a standardized manner. Cement surface was 4170.2 mm2 (3271.6-5497.8 mm2) in the syringe lavage group, whereas the jet lavage group showed 4499.3 mm2 (3354.3-5809.1 mm2); cement volume was significantly higher as well (4143.4 mm3 (2956.6-6198.6 mm3) compared with 5936.9 mm3 (3077.5-8183.1 mm3)). Cement penetration depth was 2.5 mm (1.7-3.2 mm) for the jet lavage, and 1.8 mm (1.2-2.4 mm) for the syringe lavage. The mean fracture load was 4680 N in the jet lavage group and 3800 N in the syringe lavage group (p = 0.001). Subsidence was significantly higher for syringe lavage. This study suggests a correlation of cement penetration depth and cement volume to implant failure in the tibial component of a UKA using a cadaveric model. The type of bone lavage most likely influences these two key parameters.

Pediatric patient with a bilateral Salter-Harris II fracture and slipped capital femoral epiphysis secondary to autosomal recessive osteopetrosis.

Treatment of femoral neck fractures secondary to osteopetrosis is an uncertain and puzzled decision. Experience in the treatment, especially in the pediatric population, is scarcely reported. The duration of conservative treatment is prolonged and poses the risks of non-union and development of coxa vara deformity. The recommended treatment is closed reduction and internal fixation; however, surgery on osteopetrotic bone is challenging due to defective bone marrow function, delayed consolidation and higher risk of intraoperative fractures. Slipped capital femoral epiphysis secondary to osteopetrosis is very rarely reported. This article presents the case of a 5-year-old female patient with rapidly deteriorating physical function due to bilateral proximal femoral Salter-Harris type II fractures with associated slippage of the growth plates secondary to confirmed autosomal recessive osteopetrosis. Operative treatment was performed in a tertiary level orthopedic center with closed reduction and internal fixation with cannulated screws. A loss of fixation with coxa vara deformity was seen on the left side 7 months postoperatively with increasing pain. A revision surgery with reosteosynthesis and a valgus osteotomy was thus performed which showed good subjective and objective results 1 year postoperatively with complete bony union.

Does tibial design modification improve implant stability for total knee arthroplasty? An experimental cadaver study.

AIMS: One of the main causes of tibial revision surgery for total knee arthroplasty is aseptic loosening. Therefore, stable fixation between the tibial component and the cement, and between the tibial component and the bone, is essential. A factor that could influence the implant stability is the implant design, with its different variations. In an existing implant system, the tibial component was modified by adding cement pockets. The aim of this experimental in vitro study was to investigate whether additional cement pockets on the underside of the tibial component could improve implant stability. The relative motion between implant and bone, the maximum pull-out force, the tibial cement mantle, and a possible path from the bone marrow to the metal-cement interface were determined. METHODS: A tibial component with (group S: Attune S+) and without (group A: Attune) additional cement pockets was implanted in 15 fresh-frozen human leg pairs. The relative motion was determined under dynamic loading (extension-flexion 20° to 50°, load-level 1,200 to 2,100 N) with subsequent determination of the maximum pull-out force. In addition, the cement mantle was analyzed radiologically for possible defects, the tibia base cement adhesion, and preoperative bone mineral density (BMD). RESULTS: The BMD showed no statistically significant difference between both groups. Group A showed for all load levels significantly higher maximum relative motion compared to group S for 20° and 50° flexion. Group S improved the maximum failure load significantly compared to group A without additional cement pockets. Group S showed a significantly increased cement adhesion compared to group A. The cement penetration and cement mantle defect analysis showed no significant differences between both groups. CONCLUSION: From a biomechanical point of view, the additional cement pockets of the component have improved the fixation performance of the implant. Cite this article: Bone Joint Res 2022;11(4):229-238.

Cement debonding behaviors of the various tibial components of the ATTUNE knee system and its predecessors: Is a cement-in-cement revision an alternative?

BACKGROUND: Aseptic loosening remains one of the most common causes of revision of the tibial component for total knee arthroplasty. A stable bond between implant and cement is essential for appropriate long-term results. The aim of our in vitro study was to investigate the maximum failure load of tibial ATTUNE prosthesis design alternatives compared with a previous design. In addition, cement-in-cement revision was considered as a potential strategy after tibial component debonding. METHODS: The experimental investigations of the maximum failure load of the implant-cement interface were performed under optimal conditions, without potential contamination. We compared the designs of the tibial components of the ATTUNE, ATTUNE S+ and P.F.C. Sigma. In addition, we investigated the cement-in-cement revision for the ATTUNE knee system replacing it with an ATTUNE S+. RESULTS: The maximum failure load showed no significant difference between P.F.C. Sigma and ATTUNE groups (P = 0.087), but there was a significant difference between the P.F.C. Sigma and the ATTUNE S+ groups (P < 0.001). The analysis also showed a significant difference (P < 0.001) between the ATTUNE and the ATTUNE S+ groups for the maximum failure load. The ATTUNE S+ cement-in-cement revision group showed a significant higher failure load (P < 0.001) compared with the P.F.C. Sigma and ATTUNE groups. No significant differences (P = 1.000) were found between the ATTUNE S+ cement-in-cement and ATTUNE S+ group. CONCLUSION: Based on these results, we found no design-specific evidence of increased debonding risk with the ATTUNE and ATTUNE S+ components compared with the P.F.C Sigma. Furthermore, the cement-in-cement revision seems to be an alternative for the revision surgery.

[Intervertebral disc-related occupational diseases of the lumbar and cervical spines]. / Bandscheibenbedingte Berufskrankheiten der Lenden- und Halswirbelsäule.

Intervertebral disc-related diseases of the cervical and lumbar spine are considered to be occupational diseases, if the occupational and medical prerequisites are fulfilled and the causal connection between the prerequisites is likely. The working conditions include occupational burdens with long-term lifting and carrying of heavy loads or long-term activities in an extremely bent position of the torso, long-term carrying of heavy loads on the shoulders and long-term effects of whole-body vibration in a sitting position. A medical prerequisite is fulfilled by a damage pattern with chronic lower back or neck pain and damage of the cervical or lumbar vertebrae in a conform manner.In the legal assessment the occupational conditions are examined by the preventive services of the statutory accident insurance and the medical conditions by the medical expert. Furthermore, the medical expert examines the causal connection between the fulfilled prerequisites, whereby the temporal connection (reaching the minimum load dose before realization of the conform damage pattern) and by exclusion of other competing factors are essential. As of 1 January 2021 the necessity to quit the burdening occupation has been omitted by law.

Early tibial loosening of the cemented ATTUNE knee arthroplasty - Just a question of design?

BACKGROUND: Total knee arthroplasty is a very successful standard treatment for severe osteoarthritis. Nevertheless, the literature reports tibial debonding between implant and bone cement as well as radiolucent lines related to the tibial components of different knee systems. Regardless of cementing techniques and the influences during surgery, we examined the design of a newly developed knee system and its predecessors (Attune, Attune S+, P.F.C. Sigma, P.F.C. Sigma RP/M.B.T., all DePuy). METHODS: We investigated the dimensions of the tibial components and the fit between them and their bone bed after instrumentation in a foam material. RESULTS: Our results showed considerable differences for the used knee prostheses as well as their tibial instrumentation options with a corresponding risk for incomplete seating. CONCLUSION: The orthopedic surgeons need to be aware of these design features and the resulting increased seating resistance especially in hard and sclerotic bone. ARTICLE FOCUS: Comparison of the tibial instruments and the different design options of the Attune knee system and its predecessor knee prostheses. KEY MESSAGES: The Attune implant showed incomplete seating because of too much press fit and an uneven bone quality or sclerosis can result in tilting of the tibial component. STRENGTHS AND LIMITATIONS: This is the first study investigating the Attune knee and its predecessor in terms of implant seating and press fit. The foam material is a limitation.

[Diagnostics and therapy of back pain: what is advisable? What should be avoided and why is it still done?] / Diagnostik und Therapie von Rückenschmerzen: Was ist empfehlenswert? Was sollte unterbleiben und warum wird es dennoch gemacht?

Diagnostic and therapeutic procedures are popular and frequently performed for low back pain. This narrative review presents and discusses the myths and evidence related to these procedures.In most cases it is nonspecific pain, for which no underlying disease can be named. Image diagnostics using X­rays and MRI are rarely helpful in the case of new nonspecific back pain.Evidence for chirotherapy is doubtful. Also, evidence is lacking for invasive and surgical procedures in local and regional low back pain. These procedures show superiority in radicular pain only: extraction of disc herniation in acute and subacute leg pain and segmental lumbar fusion in chronic leg pain. Nevertheless, these and other invasive methods are being used to an increasing extent. Spontaneous healing and the possibilities of the patient to become pain-relieving for themselves are neglected and increased risks are accepted.Therapeutic approaches fostering self-efficacy by reconditioning physical and mental capability and improving positive self-perception ("interdisciplinary multimodal pain therapy") effect superior and sustainable results in subacute and chronic nonspecific back pain. Patients and physicians, however, tend to prefer passive and invasive therapy strategies. The underlying mechanisms should be understood. New thinking is necessary.

Obesity, depression and hip pain.

INTRODUCTION: Up to 64% of the general population reports experiencing chronic pain, with the hip being one of the most frequent sites. An association has been shown between chronic back pain, obesity and depression. To date, a similar association has not been investigated with chronic hip pain. METHODS: A total of 2,515 subjects were chosen as a representative cross-section of the German population. Each was provided with a questionnaire that included the Regional Pain Scale, European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ-C30), Beck Depression Inventory-Primary Care and Winkler social class index. Participant height and weight values were obtained from self-reports. Using logistic regression methodology, we analysed the association between hip pain, obesity and increased depression scores. RESULTS: A total of 124 (4.9%) subjects reported chronic hip pain and an additional 39 (1.5%) reported chronic hip pain that was disabling. Hip pain affected 1-5 sites (oligolocular) in 47% of cases, and was widespread (6-19 sites) in 50%. Obesity and increased values on the depression scale were associated with an increased likelihood of chronic hip pain (odds ratio [OR] 2.55 and 8.53, respectively) compared with subjects without pain. Increased values on the depression scale (OR 28.22) increased the likelihood of experiencing disabling chronic hip pain in comparison with pain free individuals. CONCLUSIONS: Hip pain is rarely the sole site of pain. Obesity and increased values on the depression scale are associated with chronic hip pain. Increased values on the depression scale are associated with disabling chronic hip pain.

BK 2108 - The Calculation of the Normalized Relative Lumbar Disc Height. / BK 2108 ­ Die Berechnung der normierten relativen lumbalen Bandscheibenhöhe.

The assessment of the medical conditions (liability-compliant causality) of the BK 2108 is a frequent assessment, which poses a challenge to the medical expert in orthopaedics and trauma surgery. In assessing the load-consistent damage pattern, defined changes in the intervertebral discs as well as the adjacent vertebral bodies must be comprehended in a standardised manner. Of several technical measuring methods, three practicable methods are discussed and their application explained. Thus, methods are provided which allow the medical expert to calculate the normalised relative disc height. In this way, the specifications of the consensus recommendations can be met in order to define the damage profile.

Can intraoperative measurement of bone quality help in decision making for cementless unicompartmental knee arthroplasty?

BACKGROUND: In uncemented total hip arthroplasty (THA), low bone mineral density (BMD) is associated with aseptic loosening. BMD is usually assessed via dual-energy X-ray absorptiometry (DXA) or quantitative computed tomography, which takes time and exposes patients to radiation. Due to its low risk profile, intraoperative measurement of the trabecular stability might be a useful alternative to DXA. METHODS: In 24 human femora, BMD was analysed using DXA at the femoral necks and the knees. Performing the standard Oxford Unicompartmental Knee Arthroplasty (OUKA) implantation procedure, a wingblade (DensiProbe) coupled to a torque probe was used to evaluate the trabecular peak torque. The standard procedure was modified: before the completion of the central peg drill hole, the DensiProbe was inserted into the pre-drilled hole and then turned until a loss of resistance was achieved. The obtained data was then correlated with BMD at the femoral neck as well as the knee. RESULTS: In all tested regions, a higher peak torque was observed in correlation with a higher BMD. CONCLUSIONS: As demonstrated, the DensiProbe can be a helpful tool to assess the bone quality intraoperatively in OUKA. It can be a valuable decision guidance when faced with choosing between a cemented and a cementless implant. Due to the fact that the central peg hole of the OUKA can be used for the procedure, no additional risk for the patient exists, while the additional work for the surgeon is minimal.