Nerve Palsy following Reconstruction around the Knee in Musculoskeletal Oncology – A Single Institutional Experience of 30 Cases in a Quarternary Cancer Centre from India

Dr Abrar Mapkar ^*1, Dr Pramod S Chinder ², Dr Nithin T. Asadhi³

 

1,2,3. Department of Musculoskeletal Oncology, HCG Cancer Centre, Bengaluru, India.

*Correspondence to: Dr Abrar Mapkar, Department of Musculoskeletal Oncology, HCG Cancer Centre, Bengaluru, India.

Copyright.

© 2025 Dr Abrar Mapkar This is an open access article distributed under the Creative Commons Attribution   License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Received: 10 February 2025

Published: 19 February 2025

DOI: https://doi.org/10.5281/zenodo.14903685

Introduction

The 21st century has shifted the paradigm in surgical management of most limb malignancies, making limb salvage not just an option, but the norm, as a result of effective adjuvant therapy, superior imaging, improved surgical technique and advanced biomaterials and mechanics [1]. Nowadays, more than 80% of the patients are treated with limb salvage surgery without critically compromising oncological principles [2]. The knee region, consisting of the proximal tibia, distal femur and the surrounding soft tissue, is the commonest site of predilection for primary bone tumors. In the knee, the distal femur is the most common site, followed in descending order by proximal tibia [3-7]. 

In limb-salvage surgery for bone tumor, there are 3 main ways to reconstruct the bone defect after tumor resection: auto graft or allograft, inactivation and re-implantation, and artificial prosthesis replacement [8]. Allografts and endo prostheses are the most commonly used replacements for the osteo articular defect resulting from en bloc resection of primary malignant bone tumors from the distal femur or proximal tibia [9-11].

Mastering limb salvage procedures are technically demanding endeavors, with a long learning curve. The knee is an anatomically complex site, which requires the surgeon undertaking a limb salvage procedure in this region to have an intricate knowledge regarding the musculoskeletal anatomy as well as the neurovascular course. Pre-operative radiological planning is essential in determining the complete extent of the tumor, ascertaining course of the neurovascular structures with respect to tumor, and involvement if any within the tumor. Visualizing the best approach for excision of tumors with adequate margins and at the same time making sure that neurovascular bundle is safe and adequate soft tissue is left behind for reconstruction for an optimal functional outcome is key.

In spite of the strides made in the execution of limb salvage surgeries, there are a host of complications that have been reported in the literature, including infection, wound necrosis, nerve palsy, nonunion, mechanical implant failure, and vascular compromise [12-13]

Nerve palsy following limb salvage for tumors around the knee joint are one of the most jeopardizing complications seen from a functional outcome point of view. Anatomically, the major motor nerves affected in this region are the sciatic nerve and its components tibial and common peroneal nerve (CPN) [14]. Literature on this specific complication is scarce and with this paper we aim to dive into the aspects and natural course of this specific complication so as to give surgeons just starting out in the field of musculoskeletal oncology a perspective.

 

Materials and Methods

This study was conducted in HCG Cancer Centre Bangalore, a tertiary care cancer center. Retrospective search of the sarcoma registry was done. Out of a total of 8124 operated cases of sarcoma, approximately 3000 cases of limb salvage cases were isolated, and 815 of these involved tumors around the knee. 31 cases met our inclusion criteria.

Based on the pathology, patients were either started on standard neo-adjuvant chemotherapy or were planned for upfront surgery.

Preoperative planning was done with radiological evaluation consisting of CT and MRI, and the neurovascular bundle course was ascertained with respect to tumor. All surgeries were performed by a single team, in accordance with the principles of limb salvage surgeries.

Based on intraoperative findings with regards to the proximity of the nerve to tumor, we devised a classification system for nerve dissection – “Pramod and Abrar” Classification of nerve dissection.

 

Table 1 – Classification of nerve dissection

Image 1 – 29/M with an Ewings sarcoma of the proximal tibia, wherein nerve was “Retracted” in preparation of a pedicled autograft recycling with liquid nitrogen.

Image 2 – 11/M with an osteosarcoma of the distal femur, wherein nerve was “Isolated” in preparation for an autograft recycling and reconstruction with ECRT.

Image 3 - 8/M with an Osteosarcoma of the distal femur,completely involving the quadriceps wherein the nerve was “Separated” from the tumor margin followed by a nail cement spacer

Image 4 – 22/M with an osteosarcoma of the distal femur and proximal tibia, completely encasing the sciatic nerve wherein “Epineural dissection” was done followed by implantation of tumor prosthesis

 

Functional outcomes, oncological outcome and complications were evaluated by Musculoskeletal Tumor Society score⁽²²⁾, clinical and radiological examinations.

Table 2 – MSTS scoring system

 

Study Design:

Type of study – Retrospective study

Sample size - All patients who underwent tumor resection and reconstruction around the knee joint with postoperative nerve palsy were included in the study.

 

Selection of subjects:

Inclusion criteria –

1. Patients who underwent limb salvage surgery and reconstruction for tumor around the knee joint, and had postoperative nerve palsy, and with a minimum of 2 years follow-up.

 

Exclusion criteria –

1. Patients with pre-operative nerve palsy

2. Patients who had previously undergone oops surgery

3. Patients with a pathological fracture at presentation

 

Study Protocol:

All surgeries were performed by a single surgeon, in adherence to general principles of limb salvage surgery, with affected bone removed with a cuff of muscle and along with biopsy tract, and reconstruction performed. All patients gave written informed consent for participating in the study in their own native language. Study approval was obtained from our institutional review board. Regular follow up was done and essential imaging and clinical assessments were done time to time.

 

Statistical Analysis:

The data was analyzed with SPSS software version 21.0. Interpretation and analysis of obtained results was carried out using descriptive statistics. Functional outcomes, oncological outcome and complications were evaluated by Musculoskeletal Tumor Society score, clinical and radiological examinations.

Source of Funding – None

 

Results

31 Patients who underwent limb salvage surgery and reconstruction for tumor around the knee joint, and had postoperative nerve palsy, and with a minimum of 2 years follow up were included in the study.

The mean age was 22± 13.8. 17 (54.8%) were females and 14 (45.2%) were males.

Out of 31 patients, 21(67%) were diagnosed with osteosarcoma, 4(12.9%) were diagnosed with Ewing’s sarcoma, 3 (9.7%) were diagnosed with Giant cell tumor, 2(6.5%) with fibromyxoid sarcoma and 1(3.2%) with chondrosarcoma.

These tumors involved Proximal tibia in 16(51.6%) cases, distal femur in 13(41.9%) cases and both proximal tibia and distal femur in 2(6.4%) cases.

As part of the limb salvage surgeries, 14(45%) patients underwent biological reconstruction (allograft/recycled auto graft), 12(38.7%) patients underwent endo prosthetic reconstruction, resection followed by nail cement spacer was done in 3(9.6%) patients and curettage with cementing and plate fixation in 2(6.4%) patients.

As per our classification of nerve dissection, the nerve was epineurally dissected in 2(6.5%) of patients, separated in 10(32.3%) of patients, isolated in 13(41.9%) patients and retracted in (19.4%) patients.

 

Nerve isolation	Time(median(IQR))	p-value
Separated(N=10)	9(1.5)	0.009*(<0.05)
Retraced and Isolated(N=18)	6(3)

Table 3 - Comparison of nerve isolation in terms of time till recovery

 

Both patients in whom epineural dissection was performed, there was no recovery from palsy observed at 2 years.

Patients in whom the nerve was “separated” took a mean time of 9±1.5 months until recovery and the patients in whom the nerve was “retracted/isolated” took a mean time of 6±3 months until recovery.

Mean duration of surgery was 324±73 minutes. Mean blood loss was 410±170ml.

19(61.3%) patients developed immediate postoperative nerve palsy, while 12(38.7%) patients developed palsy on the following day.

 

Interval	Time(median(IQR))	p-value
Postop(N=16)	9(2.2)	<0.001*(<0.05)
POD1(N=12)	5(1.7)

Table 4 - Comparison for interval in terms of time till recovery

The mean±sd for time till recovery is 7±2.8.

Mean time till recovery in patients developing nerve paly on POD1 was 5±1.7 months, whle in patients who developed pot op palsy it was 9±2.2 months.

26(83.8%) of patients were given standard chemotherapy for their specific sarcoma, while 5(16.2%) did not receive any chemotherapy.

Chemotherapy	Time till recovery(median(IQR))
Yes(N=22)	8(2.7)
No(N=6)	3(6.5)

Mean time till recovery in patients developing nerve palsy postoperatively and who were receiving chemotherapy was 8±2.7 months, while in patients who were not on chemotherapy it was 3±6.5 months.

 

Chemo	MSTS(median(IQR))	p-value
Yes(N=25)	25(2)	<0.001*(<0.05)
No(N=6)	28(0.7)

Table 6 - Comparison of chemo in term of MSTS score

The mean±sd for MSTS score is 25.3±1.9.

Mean MSTS score in patients developing nerve palsy postoperatively and who were receiving chemotherapy was 25±2, while in patients who were not on chemotherapy it was 28±0.7.

Gender		Counts		% of Total
F		17		54.8 %
M		14		45.2 %

Fig 1

Table 1: Frequencies of Diagnosis
Diagnosis		Counts		% of Total		Cumulative %
OSTEOSARCOMA		21		67 %		64.5 %
FIBROMYXOID SARCOMA		2		6.5 %		71.0 %
GIANT CELL TUMOR		3		9.7 %		80.6 %
EWINGS SARCOMA		4		12.9 %		93.5 %
CHONDROSARCOMA		1		3.2 %		96.8 %

 

PALSY		Counts		% of Total
PROXIMAL TIBIA		16		51.6 %
DISTAL FEMUR		13		41.9 %
DISTAL FEMUR AND PROX TIBIA		2		6.4 %

 

 

 

 

 

 

 

Fig 3: Palsy

 

Procedure		Counts		% of Total
WLE+AUTOGRAFT RECYCLED RECON		14		45.1 %
WLE+RECON WITH MEGAPROSTHESIS		12		38.7%
RESECTION WITH NAIL CEMENT SPACER		3		9.6 %
ETENDED CURETTAGE+CEMENT+PLATE		2		6.4 %

Fig 4: Procedure

Nerveisolation		Counts		% of Total
ISOLATED		13		41.9 %
SEPARATED		10		32.3 %
RETRACTED		6		19.4 %
EPINEURAL DISSECTION		2		6.5 %

Interval		Counts		% of Total
POD1		12		38.7 %
POST OP		19		61.3 %

 

 

 

 

 

Fig 6: Interval

 

Interval		isolation2		Counts		% of Total
POD1		ISOLATED		7		22.6 %
		SEPARATED		0		0.0 %
		RETRACTED		5		16.1 %
		EPINEURAL DISSECTION		0		0.0 %
POST OP		ISOLATED		6		19.4 %
		SEPARATED		10		32.3 %
		RETRACTED		1		3.2 %
		EPINEURAL DISSECTION		2		6.5 %

Fig 7: POD1

Fig 8: Post Op

Frequencies of Chemo
Chemo		Counts		% of Total		Cumulative %
MAP		17		60.7 %		60.7 %
NONE		5		17.9 %		78.6 %
VAC IE		4		14.3 %		92.9 %
CISPLAT-DOX		2		7.1 %		100.0 %

 

Inferential Statistics

The test used for comparing nerve isolation, interval and adj. chemo in terms of time till recovery and MSTS score is the non-parametric Mann Whitney test.IQR gives the spread of data, i.e, how much dispersed is the other data points from the median.

 

Discussion

Tumors about the knee present one of the greatest opportunities for limb salvage, because this is the region most usually affected by the osteosarcoma and because it is the joint where reconstruction is practical to achieve after limb salvage resection ^[18]. Approximately 60-80% of osteosarcomas are located around the knee ^[19].

On retrospective analysis of our sarcoma registry, of a total of 815 cases of tumors around the knee were isolated, with 31 of these cases developing postoperative nerve palsy after tumor excision and reconstruction around the knee (3.8%).

W.Sim et al performed a retrospective analysis of consecutive resections and endo prosthetic reconstructions for tumors around the knee between 1996 and September 2005 performed at St Vincent’s Hospital, Melbourne. Fifty consecutive cases were reviewed, with a median follow-up of 24.5 (range, 2-124) months. There were five cases of postoperative nerve palsies (10%), with four affecting the common peroneal nerve and one involving the deep peroneal nerve. In the latter case, the nerve was sacrificed due to tumor envelopment. A multidisciplinary approach to management was adopted with physiotherapy, occupational therapy and orthotics being involved. An ankle-foot orthosis was provided to aid patients with foot drop. There was resolution within six months of initial surgery in three cases ^[1].

Zimri FK et al in his descriptive case series documented the clinical presentation of tumors around the knee and explored the outcome of lower limb salvage with oncological resections and mega prosthetic reconstructions, observed over a follow up period of 5-years with the study spanning over a period of 13 years. Out of 73 patients, there were 43 (58.90%) males and 30 (41.09%) females. Their ages ranged between 16–53 years with a mean of 32.97±10.68 years. The tumors included giant cell tumors (n=41), osteosarcomas (n=24), Spindle cell sarcoma (n=5), chondrosarcoma (n=2) and Ewing’s sarcoma (n=1). The average postoperative musculoskeletal tumor society (MSTS) score was 84.65%.  Various complications encountered included superficial infections/ delayed wound healing among 9 (12.32%) patients, local recurrence in 6 (8.21%), deep infections among 5 (6.84%) and transient palsy of peroneal nerve in 3 (4.10%) cases. ^[15]

Neuropraxia is the simplest form of nerve injury and is most likely to result in complete recovery. With this injury pattern, the nerve's myelin covering is damaged, hence the diminished signal. However, the actual nerve pathway is not harmed. Once the Schwann cells rebuild the myelin sheath, the nerve function should fully recover. It is this type of nerve injury that results in a palsy in patients in whom the nerve was “isolated” or “retracted”.

The intermediate nerve injury level is axonotmesis. Here the actual nerve pathway, as opposed to the covering only, is damaged. The surrounding nerve sheath is still intact, but there is axonal discontinuity. Wallerian degeneration occurs, and partial to full recovery can be expected.  It is this type of nerve injury that results in a palsy in patients in whom the nerve was “separated”.

Finally, neurotmesis occurs when the axon, myelin, and connective tissue components are damaged, disrupted, or transected, and is the most severe form of nerve injury. Recovery from neurotmesis requires surgical intervention, and the likelihood of full recovery is much lower. Tran- section of a nerve with a surgical saw blade or cautery would cause this devastating nerve insult ^[23]. It is this type of palsy that usually manifests in patients in whom the nerve was “epineurally dissected”.

To decrease the risk of making the nerve “angry” and development of a postoperative palsy as a result of dissection, we recommend a “no holding” technique of nerve dissection wherein a jet of normal saline is sprayed with the help of a syringe and needle hub cap onto the nerve soft-tissue interface while at the same time pushing the nerve using a small periosteum, separating it from adherent tissue.

Image 5 – Nerve dissection technique.

 

In case of postoperative nerve palsy, detected either immediate postoperatively or on the next day, we advise to follow our “Post Nerve Palsy Checklist”.

This includes loosening of the dressing, to eliminate any constriction effect, keeping the knee in a flexed position of 15?, to reduce nerve stretch and application of a derotation boot, especially in cases where rotating platform prosthesis are implanted, to prevent external rotation of limb and undue pressure on nerve at the level of fibular head.

Neuromodulators such as vitamin B12 and pregabalin (300mg per day) should be commenced. Pregabalin is effective in the treatment of peripheral and central neuropathic pain⁽²⁴⁾. Steroid medication inhibits the inflammatory response and consequently the recruitment of macrophages. The presence of such cells close to the site of damage has been shown to accelerate nerve regeneration in the short term⁽²⁵⁾.

In all cases of nerve palsy, clinical evaluation for the presence of compartment syndrome must be done and in case of any doubt, CT angiography must be performed at the earliest, or re-exploration in low resource setting.

 

Table 7 – Post Operative Nerve Palsy checklist

Please click here to view all figures

 

Conclusion

Nerve palsy following tumor excision and reconstruction around the knee joint, from a functional long term perspective, is a demoralizing complication, both for the surgeon as well as the patient. With the results of our study, surgeons just starting in the field of orthopedic oncology must understand that most nerve palsies recover completely, albeit delayed in patients receiving chemotherapy. Intricate preoperative planning, with use of modern tools such as 3D segmentation, and with the help of our radiology colleagues must be done, to map out the course of the neurovascular bundle with respect to the tumor, to mitigate inadvertent injury. Nerve dissection itself should be gentle and in case of postoperative nerve palsy, our “Post Palsy Checklist” must be followed.

Patient education in the form of thorough preoperative counselling must be done, to keep them well informed of a potential of risk of nerve palsy postoperatively.

Further research is warranted in the form of prospective studies, using the modality of nerve conduction studies and other advanced studies, to deepen our knowledge on the pathophysiology and natural course of this complication, and also to ascertain the cause of the enigmatic palsy that sets in the day after the surgery (POD1).

 

 

References

1. I.-W. Sim, L.F. Tse, E.T. Ek, G.J. Powell, P.F.M. Choong, Salvaging the limb salvage: Management of complications following endoprosthetic reconstruction for tumours around the knee,European Journal of Surgical Oncology (EJSO),Volume 33, Issue 6,2007,Pages 796-802,ISSN 0748-7983

2. Zhao J, Xu M, Zheng K, Yu X. Limb salvage surgery with joint preservation for malignant humeral bone tumors: operative procedures and clinical application. BMC Surg. 2019 May 30;19(1):57

3. Robert, R. S., Ottaviani, G., Huh, W. W., Palla, S., and Jaffe, N. 2010. “Psychosocial and Functional Outcomes in Long-Term Survivors of Osteosarcoma: A Comparison of Limb-Salvage Surgery and Amputation.” Pediatr Blood Cancer 54 (7): 990-9.

4. Gibbs, C. P. Jr,, Weber, K., and Scarborough, M. T. 2001. “Malignant Bone Tumors.” J. Bone Joint Surg. (Am) 83 (11): 1728-45.

5. Malawer, M. M., and Chou, L. B. 1995. “Prosthetic Survival and Clinical Results with Use of Large-Segment Replacements in the Treatment of High-Grade Bone Sarcomas.” J. Bone Joint Surg. (Am) 77 (8): 1154-65.

6. Mirabello, L., Troisi, R. J., and Savage, S. A. 2009. “International Osteosarcoma Incidence Patterns in Children and Adolescents, Middle Ages and Elderly Persons.” Int. J. Cancer 125 (1): 229-34.

7. Jaffe, N. 2009. “Osteosarcoma: Review of the Past, Impact on the Future. The American Experience.” Cancer Treatment and Research 152: 239-62.

8. Zhang H. Application and Development of Megaprostheses in Limb Salvage for Bone Tumors Around the Knee Joint. Cancer Control. 2022;29.

9. Kneels JS, Finn HA, Simon MA: Mobile knee reconstructions after resection of malignant tumors of the distal femur. Orthop Cline North Am 1991;22:105±119.

10.  Sim FH, Beacham CP, Cah EY: Reconstruction of musculoskeletal defects about the knee for tumor. Cline Orthop 1987;221: 188±201.

11.  Simon MA: Current concepts review: Limb salvage for osteosarcoma. J Bone Joint Surg Am 1988;70:307±310.

12. Marcove, R. C., and Rosen, G.: En bloc resections for osteogenic sarcoma. Cancer 45:3040, 1980.

13. Morton, D. L., Eilber, F. R., Townsend, C. M., Grant, T. T., Mirra, J., and Weisenburger, T. H.: Limb salvage from a multidisciplinary treatment ap- proachfor skeletal and soft tissue sarcomas of the extremity. Ann. Surg. 184:268, 1976

14. Thatte MR, Hiremath A, Goklani MS, Patel NR, Takwale AB. Peripheral Nerve Injury to the Lower Limb: Repair and Secondary Reconstruction. Indian J Plast Surg. 2019 Jan;52(1):93-99.

15. Zimri FK, Saaiq M, Noman M, Qayyum F. Lower Limb Salvage For Tumours Around The Knee Using Oncological Resections And Megaprosthetic Reconstructions. J Ayub Med Coll Abbottabad. 2023 Feb-Mar;35(1):27-31.

16. Mavrogenis AF, Mitsiokapa EA, Sakellariou VI, Tzanos G, Papagelopoulos PJ. Functional and radiographic outcome after tumor limb salvage surgery using STANMORE megaprostheses. J BUON. 2011 Apr-Jun;16(2):353-60.

17. Zou, C., Zhao, Z., Lin, T. et al. Long-term outcomes of limb salvage treatment with custom-made extendible endoprosthesis for bone sarcoma around the knee in children. J Orthop Surg Res 15, 14 (2020).

18. FINN, H.A. & SIMON, M.A.- Limb salvage surgery in the treatment of osteosarcoma in skeletally inmature individuals. Clin Orthop 262:108-118, 1991.

19. SWEETNAM, M.A. Malignant bone tumor management. 30 years of achievement. Clin Orthop 247:67-73, 1989.

20.  Trieb K, Göggel M, Dürr HR. Proximaler Tibiaersatz mit Transfer des M. Gastrocnemius [Proximal tibial reconstruction with gastrocnemius flap]. Oper Orthop Traumatol. 2012 Jul;24(3):263-9. German.

21. Carender CN, Bedard NA, An Q, Brown TS. Common Peroneal Nerve Injury and Recovery after Total Knee Arthroplasty: A Systematic Review. Arthroplast Today. 2020 Aug 22;6(4):662-667.

22. Sherling, N., Yilmaz, M., Holm, C.E. et al. Validity of the Musculoskeletal Tumor Society Score for lower extremity in patients with bone sarcoma or giant cell tumour of bone undergoing bone resection and reconstruction surgery in hip and knee. BMC Cancer 24, 1019 (2024). https://doi.org/10.1186/s12885-024-12686-9

23. Nerve Injuries, Orthop Clin N Am 53 (2022) 123-127https://doi.org/10.1016/j.ocl.2021.11.002

24. Singh RK, Sinha VP, Pal US, Yadav SC, Singh MK. Pregabalin in post traumatic neuropathic pain: Case studies. Natl J Maxillofac Surg. 2012 Jan;3(1):91-5. doi: 10.4103/0975-5950.102175. PMID: 23251069; PMCID: PMC3513820.

25. Rahim Mohammadi, Mahboobeh Azad-Tirgan, Keyvan Amini, Dexamethasone topically accelerates peripheral nerve repair and target organ reinnervation: A transected sciatic nerve model in rat,Injury,Volume 44, Issue 4,2013, Pages 565-569,ISSN 0020-1383, https://doi.org/10.1016/j.injury.2012.10.013.