Custom-made lateral femoral condyle replacement for traumatic bone loss: a case report

Clinical Perspectives on Surgical Reconstruction of Eccentric Tumors at the Distal Femur with Unicondylar Resection

The distal femur is one of the most common sites for primary bone tumors. As the tumor progresses and bone destruction worsens, it can severely affect knee function and even pose a threat to life. In cases where only one condyle is affected and requires resection, preserving the healthy contralateral condyle can substantially enhance the biomechanics of the knee. Furthermore, preserving bone stock may enable future salvage procedures in the event of initial surgery failure, be it from fractures or osteoarthritis. Distal femoral unicondyle resection can offer better functional outcomes in select cases. However, it is essential to prioritize oncological safety with adequate margins over short-term knee function. Currently, the primary methods for reconstruction after the excision of a unicondylar tumor include allograft transplantation (bi- or uni-condylar) and prosthetic or allograft-prosthesis composite replacement (APC). However, there is currently some controversy regarding the optimal surgical reconstruction method, and a consensus within the academic community has yet to be reached. Moreover, due to the rarity of bone tumors, extensive clinical data from a single center is limited. Current studies are mainly retrospective and single-center, lacking sufficient cases and follow-up duration. This article reviews surgical reconstruction after solitary condylar excision in distal femoral tumors. It summarizes, compares, and analyzes mainstream reconstruction methods, exploring their technical details and clinical outcomes to highlight their potential in bone oncology.

Manufacturing Polymer Model of Anatomical Structures with Increased Accuracy Using CAx and AM Systems for Planning Orthopedic Procedures

Currently, medicine uses typical industrial structure techniques, including reverse engineering, data processing, 3D-CAD modeling, 3D printing, and coordinate measurement techniques. Taking this into account, one can notice the applications of procedures used in the aviation or automotive industries based on the structure of Industry 4.0 in the planning of operations and the production of medical models with high geometric accuracy. The procedure presented in the publication shortens the processing time of tomographic data and increases the reconstruction accuracy within the hip and knee joints. The procedure allows for the partial removal of metallic artifacts from the diagnostic image. Additionally, numerical models of anatomical structures, implants, and bone cement were developed in more detail by averaging the values of local segmentation thresholds. Before the model manufacturing process, additional tests of the PLA material were conducted in terms of its strength and thermal properties. Their goal was to select the appropriate type of PLA material for manufacturing models of anatomical structures. The numerical models were divided into parts before being manufactured using the Fused Filament Fabrication technique. The use of the modifier made it possible to change the density, type of filling, number of counters, and the type of supporting structure. These treatments allowed us to reduce costs and production time and increase the accuracy of the printout. The accuracy of the manufactured model geometry was verified using the MCA-II measuring arm with the MMDx100 laser head and surface roughness using a 3D Talyscan 150 profilometer. Using the procedure, a decrease in geometric deviations and amplitude parameters of the surface roughness were noticed. The models based on the presented approach allowed for detailed and meticulous treatment planning.

Custom Mega Prosthesis Knee: A Panacea for Intricate Trauma of Distal Femur with Bone Loss

Introduction:

Management of distal femoral intra-articular fracture with bone loss is an arduous endeavour. Although multiple reconstructive alternatives are available, the complexity of the fracture, amount of bone loss and the patient’s expectations determine the treatment paradigm, before contemplating the pertinent treatment option for the patient.

Case Report:

We report the case of a 47-year-old male patient involved in a road traffic accident in which he sustained an open distal femoral intra-articular fracture with substantial loss of distal femoral shaft and the entire metaphyseal regions. Reconstruction options considered include osteochondral distal femoral allograft, ilizarov bone transport, free vascularised vascularized fibular graft with/without allograft, arthrodesis, and custom megaprosthesis of the distal femur. Considering all the merits and demerits of the aforementioned options and including patient’s expectations in the treatment algorithm, custom megaprosthesis of the knee was designed and implanted. At 18 months follow-up, our patient showed gratifying results with a Musculo-skeletal Tumours Society MSTS score of 26, good articulation of the segments, no somatosensory or motor deficit, no infection, no dislocation, or periprosthetic fracture.

Conclusion:

Using megaprosthesis to treat such intricate trauma provides better reconstruction with good restoration of limb length and torsion, improving the overall functionality of the limb and patient’s psychological rehabilitation.

Custom-made lateral femoral hemiarthroplasty for traumatic bone loss: A case report

We report the case of a 32-year-old male patient involved in a road traffic accident in which he sustained a grade II open supra- and intercondylar fracture of the left distal femur with substantial bone loss of the lateral femoral condyle and trochlea (AO classification type 33 C3). Normal knee function was no longer possible, as the patella was trapped within the bony defect. Existing reconstructive options such as unicondylar osteoarticular allograft, arthrodesis, and arthroplasty were considered. However, as all these techniques present significant disadvantages, particularly in young and active patients, a custom-made lateral hemiarthroplasty was designed and implanted as an alternative treatment. Follow-up at 24 months revealed an excellent, pain-free level of function and radiographs showed no signs of implant loosening or migration. This technique offers the most anatomical means of reconstruction with maximal preservation of the bone stock, thereby better facilitating any revisions that may be necessary in the future. This is an experimental technique reserved for rare indications, and currently has no long-term follow-up results associated with its use. Additional research is therefore needed before widespread adoption of this technique can take place.

Successful hemicondylar femoral allograft for traumatic bone loss: a paediatric case study with ten years of follow-up

The management of massive traumatic defects of the knee joint is challenging, especially in children. Massive osteoarticular allograft may be an option in this kind of traumatic bone loss. We report on the case of a male patient who (at the age of 15) suffered an open grade III condylar femoral joint fracture, with a massive bone defect and a Schatzker V tibial plateau fracture. Ten years after first-line treatment with massive osteoarticular allograft of the lateral femoral condyle, the patient's knee was capable of full extension and 90° flexion. The patient reached a point of being pain free for nine years before he subsequently developed some pain with lateral arthritis progression.

27 year survival of Maney Watt unicondylar hemi knee replacement for fixation of a lateral tibial plateau fracture--a case report

We report the case of a 62-year-old gentleman who underwent a novel treatment for a lateral tibial plateau fracture 27 years ago. The patient presented to an elective knee outpatient clinic with new onset knee pain. Further investigation revealed that this was a Maney Watt prosthesis (Zimmer UK) for use in the management of unicompartmental osteoarthritis. This mode of fixation gave this patient over 20 years of good functional outcome. Following revision, the patient was followed up at 5 years, reporting a satisfactory outcome.

Autologous chondrocyte implantation for osteochondral lesions in the knee using a bilayer collagen membrane and bone graft: a two- to eight-year follow-up study

Matrix-induced autologous chondrocyte implantation (MACI) is an established technique used to treat osteochondral lesions in the knee. For larger osteochondral lesions (> 5 cm(2)) deeper than approximately 8 mm we have combined the use of two MACI membranes with impaction grafting of the subchondral bone. We report our results of 14 patients who underwent the 'bilayer collagen membrane' technique (BCMT) with a mean follow-up of 5.2 years (2 to 8). There were 12 men and two women with a mean age of 23.6 years (16 to 40). The mean size of the defect was 7.2 cm(2) (5.2 to 12 cm(2)) and were located on the medial (ten) or lateral (four) femoral condyles. The mean modified Cincinnati knee score improved from 45.1 (22 to 70) pre-operatively to 82.8 (34 to 98) at the most recent review (p < 0.05). The visual analogue pain score improved from 7.3 (4 to 10) to 1.7 (0 to 6) (p < 0.05). Twelve patients were considered to have a good or excellent clinical outcome. One graft failed at six years. The BCMT resulted in excellent functional results and durable repair of large and deep osteochondral lesions without a high incidence of graft-related complications.