Investigation of Giant Cell Tumor of Bone and Tissue Engineering Approaches for the Treatment of Giant Cell Tumor of Bone

Primary bone tumors such as Ewing sarcoma, osteosarcoma, and chondrosarcoma, secondary bone tumors developed from progressive malignancies, and metastasized bone tumors are more prevalent and studied descriptively through biology and medical research. Less than 0.2% of cancer diagnoses are caused by rare bone-originating tumors, which despite being rare are particularly difficult due to their high death rates and substantial disease burden. A giant cell tumor of bone (GCTB) is an intramurally invasive but rare and benign type of bone tumor, which seldom metastasizes. The most often prescribed medication for GCTB is Denosumab, a RANKL (receptor activator of nuclear factor κB ligand) inhibitor. Because pharmaceutical drug companies rely on two-dimensional and animal models, current approaches for investigating the diverse nature of tumors are insufficient. Cell line based medication effectiveness and toxicity studies cannot predict tumor response to antitumor medicines. It has already been investigated in detail why molecular pathways do not reproduce in vitro, a phenomenon known as flat biology. Due to physiological differences between human beings and animals, animal models do not succeed in identifying side effects of the treatment, emulating metastatic growth, and establishing the link between cancer and the immune system. This review summarizes and discusses GCTB, the disease, its cellular composition, various bone tumor models, and their properties and utilization in research. As a result, this study delves deep into in vitro testing, which is vital for scientists and physicians in various fields, including pharmacology, preclinical investigations, tissue engineering, and regenerative medicine.

The outcomes of surgical treatment for lateral Hoffa fracture nonunions

INTRODUCTION

Lateral Hoffa nonunion are rare injuries. A significant percentage of these nonunions are due to missed acute lateral Hoffa fractures. Operative management of these injuries is difficult and complicated by the presence of bone loss, infection, and soft-tissue contractures. In this study, the aim was to assess clinical and functional outcome in our group of patients with lateral Hoffa nonunion who had undergone operative management and to determine whether variables such as fracture type, infection, and previous surgery affect nonunion/complication rates.

MATERIALS AND METHODS

Data were analyzed for patients with lateral Hoffa nonunion who underwent surgical fixation from January 2008 to December 2020 at a tertiary-care referral center. Patients with lateral condyle Hoffa nonunion and having a minimal follow-up of 1 year were included in this study. Patients with medial Hoffa nonunion, pathological fractures, and children aged less than 16 years were excluded from the study. The fractures were classified by the AO/OTA and Letenneur classification systems. Clinical and functional outcomes were assessed by the Knee society score (KSS) and the lower extremity functional scale (LEFS).

RESULTS

All the 12 patients had united in our series. One patient had reduction failure at 3 months who united after re-fixation. The union rate in our patients was 100%, with a loss of reduction rate of 7.7%, and post-traumatic arthrosis of 7.7%. The average follow-up period was 52.16 ± 27.7 months. The mean knee flexion obtained at the final follow-up was 104.5° (80°-130°). The average KSS clinical score was 80.6 (65-88). The average KSS functional score was 92 (70-100). The average LEFS score was 71 (47-79). There is a statistically significant improvement in the knee range of motion in our patients (p = 0.001). However, no correlation could be detected between variables like type of fracture, infection, and previous surgeries and outcomes.

CONCLUSIONS

Lateral Hoffa nonunion can be managed with careful planning of surgical approaches and fixation techniques.

The radial nerve at revision/redo surgery - using the lower lateral cutaneous nerve to prevent a postoperative radial nerve deficit

Background

The posterior approach to the humeral shaft is commonly used for surgical procedures on the humeral shaft. We present our experiences using the modification of the surgical exposure described by Gerwin M. which we have found useful at the time of revision surgery.

Methods

Between 2014 and 2019, six patients who underwent a revision surgical procedure for a nonunion of the humeral shaft where a prior surgical procedure was performed through a posterior incision were included. The approach used a modification of the posterior approach described by Gerwin M. where the lower lateral cutaneous nerve branch of the radial nerve is used to identify trace, mobilize, retract, and protect the radial nerve to achieve adequate exposure of the humeral shaft.

Results and Discussion

None of the patients had a postoperative nerve deficit.Adequate exposure to aid hardware removal, osteosynthesis, and bone grafting was achieved in all patients.

Conclusion

The modification of the posterior approach described by Gerwin M. is useful at the time of revision or redo surgery on the humeral shaft where other bony and soft tissue landmarks are altered to prevent an iatrogenic injury to the radial nerve while providing adequate exposure to treat a nonunion.

Incidence and predictors of radial nerve palsy with the anterolateral brachialis splitting approach to the humeral shaft

PURPOSE

Fractures of the humeral shaft are common and account for 3%-5% of all orthopedic injuries. This study aims to estimate the incidence of radial nerve palsy and its outcome when the anterior approach is employed and to analyze the predictive factors.

METHODS

The study was performed in the department of orthopaedics unit of a tertiary care trauma referral center. Patients who underwent surgery for acute fractures and nonunions of humerus shaft through an anterior approach from January 2007 to December 2012 were included. We retrospectively analyzed medical records, including radiographs and discharge summaries, demographic data, surgical procedures prior to our index surgery, AO fracture type and level of fracture or nonunion, experience of the operating surgeon, time of the day when surgery was performed, and radial nerve palsy with its recovery condition. The level of humerus shaft fracture or nonunion was divided into upper third, middle third and lower third. Irrespective of prior surgeries done elsewhere, the first surgery done in our institute through an anterior approach was considered as the index surgery and subsequent surgical exposures were considered as secondary procedures.

RESULTS

Of 85 patients included, 19 had preoperative radial nerve palsy. Eleven (16%) patients developed radial nerve palsy after our index procedure. Surgeons who have two or less than two years of surgical experience were 9.2 times more likely to induce radial nerve palsy (p=0.002). Patients who had surgery between 8 p.m. and 8 a.m. were about 8 times more likely to have palsy (p=0.004). The rest risk factor is AO type A fractures, whose incidence of radial nerve palsy was 1.3 times as compared with type B fractures (p =0.338). For all the 11 patients, one was lost to follow-up and the others recovered within 6 months.

CONCLUSION

Contrary to our expectations, secondary procedures and prior multiple surgeries with failed implants and poor soft tissue were not predictive factors of postoperative deficit. From our study, we also conclude that radial nerve recovery can be reasonably expected in all patients with a postoperative palsy following the anterolateral approach.

Functional outcome of knee arthrodesis with a monorail external fixator

Several methods for obtaining knee arthrodesis have been described in the literature and world; over, the commonest cause for arthrodesis is a failed arthroplasty. Less commonly, as in this series, post-infective or traumatic causes may also require a knee fusion wherein arthroplasty may not be indicated. We present salient advantages along with the radiological and functional outcome of twenty four patients treated with a single monorail external fixator. All patients went on develop fusion at an average of 5.4 months with an average limb length discrepancy of 3 cm (1.5-6 cm). Improvements in functional outcome as assessed by the lower extremity functional score (LEFS), and the SF-36 was significant (p = 0.000). Knee arthrodesis with a single monorail external fixator is a reasonable single-staged salvage option in patients wherein arthroplasty may not be the ideal choice. The outcome, though far from ideal, is definitely positive and predictable.