Tibial stem tip pain in stemmed revision total knee arthroplasty: treatment with tension band plating

Osteoanabolic Treatment with Teriparatide for Pathological Stress Transfer After Total Hip Arthroplasty: A Case Report

CASE

Total hip arthroplasty with an uncemented, tapered, fluted stem was performed in a 79-year-old woman with known osteoporosis to treat an intertrochanteric fracture. Exertional thigh pain and cortical thickening developed at the tip of the stem. The patient was treated with teriparatide for a total of 2 years and became asymptomatic within months. Radiographs showed improved bone quality around the stem of the prosthesis, and dual-energy x-ray absorptiometry scans confirmed remineralization.

CONCLUSION

Stem tip pain is a well-known complication of distally engaging arthroplasty implants. Various surgical options have been suggested to address this condition. Teriparatide is known to help prevent fractures and improve bone healing. This successful off-label use might be of interest for the future treatment of this biomechanical complication.

Stress-Induced, Aseptic Osteolysis of the Mid-Tibia in a Revision Hinged Total Knee Arthroplasty Mimicking Infection

In this report, we present the case of an 80-year-old female with pain located over the tip of her cemented tibial stem in a revision hinge total knee arthroplasty with localized osteolysis that looked suspicious for infection. A thorough workup was negative for infection. We postulate that the osteolysis at the end of her tibial stem was initiated by a modulus of elasticity mismatch at the stem tip, which generated a focal area of increased sagittal bone bending and microparticle generation. She was treated with lesional exploration, debridement, synthetic bone grafting, and tibial plating to distribute stress loads away from the tibial stem tip. Histologic analysis identified no organisms or neoplasm. Her pain ultimately resolved, and the patient returned to her customary activities.

[End-of-stem pain in hip and knee arthroplasty]

End-of-stem pain after knee and hip arthroplasty with diaphyseal supportive stems is a frequently overlooked and potentially underestimated complication. A commonly recurring clinical phenome is the symptom-free interval after surgery of weeks to months, with new onset of symptoms under stress only later. The patient is often again reliant on walking sticks. End-of-stem pain is a diagnosis of exclusion. Pain is projected into the tip of the stem, and if differential diagnoses such as loosening are excluded, then the patient might be treated with a "bending-plate". Since bone cement has a similar elastic modulus to human cortical bone, a change of method to a cemented implant can also be expedient. In the primary situation, in addition to cemented stems, the use of "split-stems" could be useful. After revision surgery of any kind, a timely cessation of pain confirms the diagnosis.

Reduced tibial strain-shielding with extraosseous total knee arthroplasty revision system

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A novel extracortical support system for revision of failed knee prostheses.

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Shown to reduce metaphyseal stress-shielding versus intramedullary stem fixation.

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Reduces bone loss and enables bone grafting of defects after implant loosening.

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Enables use of conventional prosthesis in a revision scenario.

Background

Revision total knee arthroplasty (RTKA) has poorer results than primary total knee arthroplasty (TKA), and the prostheses are invasive and cause strain-shielding of the bones near the knee. This paper describes an RTKA system with extracortical fixation. It was hypothesised that this would reduce strain-shielding compared with intramedullary fixation.

Methods

Twelve replica tibiae were prepared for full-field optical surface strain analysis. They were either left intact, implanted with RTKA components with cemented intramedullary fixation stems, or implanted with a novel design with a tibial tray subframe supported by two extracortical fixation plates and screw fixation. They were loaded to simulate peak walking and stair climbing loads and the surface strains were measured using digital image correlation. The measurements were validated with strain gauge rosettes.

Results

Compared to the intact bone model, extracortical fixation reduced surface strain-shielding by half versus intramedullary fixation. For all load cases and bone regions examined, the extracortical implant shielded 8–27% of bone strain, whereas the intramedullary component shielded 37–56%.

Conclusions

The new fixation design, which offers less bone destruction than conventional RTKA, also reduced strain-shielding. Clinically, this design may allow greater rebuilding of bone loss, and should increase long-term fixation.

Tension Band Plating for Chronic Anterior Tibial Stress Fractures in High-Performance Athletes

BACKGROUND

Anterior tibial stress fractures are associated with high rates of delayed union and nonunion, which can be particularly devastating to a professional athlete who requires rapid return to competition. Current surgical treatment strategies include intramedullary nailing, which has satisfactory rates of fracture union but an associated risk of anterior knee pain. Anterior tension band plating is a biomechanically sound alternative treatment for these fractures.

HYPOTHESIS

Tension band plating of chronic anterior tibial stress fractures leads to rapid healing and return to physical activity and avoids the anterior knee pain associated with intramedullary nailing.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Between 2001 and 2013, there were 13 chronic anterior tibial stress fractures in 12 professional or collegiate athletes who underwent tension band plating after failing nonoperative management. Patient charts were retrospectively reviewed for demographics, injury history, and surgical details. Radiographs were used to assess time to osseous union. Follow-up notes and phone interviews were used to determine follow-up time, return to training time, and whether the patient was able to return to competition.

RESULTS

Cases included 13 stress fractures in 12 patients (9 females, 3 males). Five patients were track-and-field athletes, 4 patients played basketball, 2 patients played volleyball, and 1 was a ballet dancer. Five patients were Division I collegiate athletes and 7 were professional or Olympic athletes. Average age at time of surgery was 23.6 years (range, 20-32 years). Osseous union occurred on average at 9.6 weeks (range, 5.3-16.9 weeks) after surgery. Patients returned to training on average at 11.1 weeks (range, 5.7-20 weeks). Ninety-two percent (12/13) eventually returned to preinjury competition levels. Thirty-eight percent (5/13) underwent removal of hardware for plate prominence. There was no incidence of infection or nonunion.

CONCLUSION

Anterior tension band plating for chronic tibial stress fractures provides a reliable alternative to intramedullary nailing with excellent results. Compression plating avoids the anterior knee pain associated with intramedullary nailing but may result in symptomatic hardware requiring subsequent removal.

[Bone microindentation and pressure algometry applied to revision total knee replacement and tibial end-of-stem pain. Preliminary results in a group of twenty patients]

OBJECTIVES

To study the relationship between the appearance of end-of-stem pain with a preoperative decrease in local bone strength by using the bone microindentation technique. The potential usefulness of pressure algometry in the diagnosis and monitoring of this group of patients is also determined.

MATERIAL AND METHOD

A preliminary intra- and inter-rater correlation study was performed in a group of 50 healthy volunteers in order to validate the algometry technique. A prospective study was then conducted on 20 patients with a mean age of 74 years (range 57-84) undergoing knee prosthetic surgery with use of a cementless tibial stem. Bone microindentation and pressure algometry measurements were made preoperatively, and after one year of follow-up. The statistical analysis was performed using the Intraclass correlation coefficient and the Student t test for paired data.

RESULTS

The intra and inter-rater correlation values were excellent; 0.91 (0.84-0.95) and 0.86 (0.74-0.92), respectively. No significant variations were found in the microindentation (P=.11) or in the pressure algometry (P=.6) values after one year of follow-up. Nevertheless, a significant correlation was observed between the values for pressure algometry and the EVA (P=.002) and functional scale (P=.02) at the end of follow-up.

CONCLUSIONS

Pressure Algometry is a useful tool to evaluate this group of patients. Bone microindentation does not seem to be useful in identifying patients with increased risk of developing tibial end-of-stem pain.