Treatment of early post-operative flexion contracture after total knee arthroplasty with osteopathic manipulations| Lo Scalpello - Journal

Abstract

Flexion contracture is an unwanted complication of total knee arthroplasty (TKA), occurring in 1.4 to 17% of patients, probably secondary to an abnormal distribution of forces across the prosthetic components with an increased load in the posterior aspect of the tibial plateau and the patellofemoral joint. Several studies have advocated that residual flexion contracture after TKA may improve with time; however, contradictory results have also been reported, especially in cases with more than 15° of severe post-operative flexion contracture. Nineteen patients (19 knees) who did not have a pre-operative flexion contracture and underwent TKA surgery between January 2014 and July 2014 by a single surgeon were included in the study. Patients treated with osteopathic manipulations showed a significant improvement compared to controls. The causes of stiffness during knee flexion are often unclear even if full extension is achieved intra-operatively. We believe that there is a direct correlation between pain and stiffness and flexion of the knee, observed when the patient assumes a flexed position due to pain. Since our study shows an improvement in both pain and stiffness with osteopathic manipulative treatment (OMT), we believe that this treatment modality may be beneficial to allow early rehabilitation.

Introduction

Flexion contracture is an unwanted complication of total knee arthroplasty (TKA), occurring in 1.4 to 17% of patients ^1,2. Patients with a postoperative flexion contracture have an increased prevalence of anterior knee pain, likely secondary to an abnormal distribution of forces across the prosthetic components with an increased load in the posterior aspect of the tibial plateau and the patellofemoral joint ³. On the other hand, the majority of flexion contractures detected immediately after TKA may be attributed to the presence of pain and joint effusion ^4-6, due to the fact that patients tend to bend their knees into more comfortable positions when they experience pain and effusion. Furthermore, previous knee extension data has shown that patients with large flexion contractures preoperatively are more likely to experience a flexion contracture post-operatively ⁷. Recent evidence shows that pre-operative flexion contracture does not affect outcomes in TKA ^8,9. However, other factors must be considered. More advanced age was positively correlated with incidence of a postoperative flexion contracture greater than 10°. The chances of developing a post-operative flexion contracture greater than 10° are increased by 35% every 10 years. Patients with a higher body mass index have a lower probability of a post-operative flexion contracture, with a 35% decrease in the chance of a postoperative flexion contracture greater than 10° for every 5 units of BMI ¹⁰.

Most patients, therapists, and surgeons focus on achieving flexion in the early post-operative period. However, a persistent flexion contracture can be even more disabling than limited flexion. Ritter et al. found that post-operative flexion contracture was associated with increased pain and low knee function scores ¹⁰. Due to their deleterious effects, it is important to not allow flexion contractures to remain post-operatively even if most of these minor flexion contractures (< 15°) resolve with time and are of little clinical significance ^3,11. Hiroaki et al. ¹² also demonstrated that patients with flexion contracture of more than 15° at 3 months after surgery had difficulty achieving full extension over time. These results suggest that post-operative rehabilitation should aim to reduce flexion contracture during the initial 3 months after surgery to 10° or less. The aim of this investigation was to evaluate the effects of early osteopathic manipulative treatment (OMT) associated with standardized physical therapy on short-term outcomes compared to standardized physical therapy alone. Primary outcomes of interest include passive flexion and extension achieved (range of motion; ROM), pain visual analog scores (VAS), and swelling.

Materials and methods

Nineteen patients (19 knees) who did not have a preoperative flexion contracture and who underwent TKA surgery between January 2014 and July 2014 by a single surgeon were included in the study. Patients with a diagnosis of primary osteoarthritis, second time reimplantation for infection (one case), severe angular deformity, were included. Individuals were assigned by consecutive sequencing into one of two protocol groups, A and B (case control) during pre-operative classes. Of the 19 patients, 1 was a male and 9 were females with a mean age of 71.5 years in group A; in group B, 6 were males, 3 were females with a mean age of 70.2 years.

Surgical technique

All operations were performed following our standard institutional perioperative care protocol. Patients underwent surgery with hypotensive epidural anesthesia. A midline incision, with a medial parapatellar arthrotomy and without patella eversion, was used in all cases ¹³. The tibial cut was performed with an extramedullary guide and preceded all femoral cuts. The distal femur was then cut using an intramedullary alignment guide set at 5° of valgus with anterior referencing instrumentation. Femoral component rotation was determined using the posterior femoral condyles, the epicondylar axis, and Whiteside’s line ^14,15. The primary implant prosthesis was posteriorly stabilized with a fixed plate ^8,9. Flexion and extension gaps were balanced using spacer blocks, aiming at achieving rectangular and symmetric gaps. Therefore, it would appear that contributory factors are involved that are not easily identified intra-operatively. During intra-operative examination of the knee, the passive properties of skeletal muscle are the most readily appreciated and are used to guide clinical decisions. However, passive tension is not a good predictor of function ¹⁶. Intra-operatively it was estimated that the flexion-extension was complete. Specific treatment was performed in second stage reimplantation for infection after removal of the antibiotic spacer.

Post-operative radiographic analysis revealed no differences in the mechanical alignment of the knees in the frontal plane or in regard to tibial slope angle ^8,9. Post-operative pain control was achieved with an elastomeric pump and patient-controlled analgesia for the first 24 hours post-operatively, progressing to oral analgesics as tolerated. Drains were used in all cases and removed on the second post-operative day. PCR was monitored during hospitalization. Rehabilitation was initiated the day after surgery with a continuous passive motion (CPM) machine set from 0 to 60° for 20 minutes each time. All patients received the same physical therapy regime, which focused on active ROM and early functional mobility. Isometric exercises and walking were started on the second post-operative day ^8,9.

Two OMTs were done during hospitalization in one group. The goal of osteopathy is to identify and intervene on “somatic dysfunction” (codified in the 10^th edition of the International Classification of Diseases of the World Health Organization) through manual procedures facilitating the intrinsic ability of the organism to tend to self-healing ^8,9. All patients were allowed weight bearing as tolerated and received pharmacological thromboprophylaxis for five weeks with LMWH. Patients were discharged to home or an inpatient rehabilitation unit within four to six days after surgery.

Post-operative follow-up visits were at pre- and post-OMT. During each visit, the surgeon measured VAS, and swelling (circumference of the thigh, calf, ankle). Gravity-assisted, ROM was assessed with a goniometer preoperatively and at each subsequent post-operative visit with the patient in a supine position. Measurements were taken using plastic goniometers on the lateral aspect of the leg with patients in the supine position, using the vertical mid points of the thigh and lower leg as reference points for the arms of the goniometer. All postoperative assessments were done by the same surgeon.

Results are shown in Tables I and II.

At the first post-operative visit, the mean knee flexion contracture was -16.5° in group A and -15.3° in group B; at the last post-operative visit (after OMT), the mean flexion contracture in the study group was -7.0° versus -12.6° in the control group. Following OMT, a highly significant difference was found.

Pain also improved. At first post-operative visit, the mean VAS score was 6.6 in group A and 3.3 in group B. Atthe last post-operative visit pain was 5.6 in group A and 3.4 in the group B.

The improvement in stiffness in knee flexion was associated with improvement of the values of the VAS scale, which could represent a more objective interpretation of pain.

Moreover, the average degree of flexion at the first post-operative time switched from 52° in group A and 67° in group B to a final degree of flexion of 60° in group B versus 63° in group A at the last post-operative visit. Using v2 and Fisher’s exact tests to compare the development of a stiff knee between females and males, a weak but significant difference was found.

There were no significant differences in swelling between groups.

Discussion

Fixed flexion contracture prevents the knee from achieving full extension. It is thought to be a result of abnormalities in bony anatomy, as well as soft tissue contracture and tightness around the joint ³. Several studies have advocated that residual flexion contracture after TKA may improve with time ^17,18; however, contradictory results have also been reported, especially in cases with more than 15° of severe postoperative flexion contracture ^3,5,10-12,19. Furthermore, we believe that the reduction of flexion contracture allows an optimum load on the knee ²⁰ and an earlier recovery. The results of the current study showed there was a highly significant difference between patients treated with OMT and control cases. It is possible that the correlation between stiffness in knee flexion and VAS scale may represent a more objective parameter in the interpretation of pain because patients tend to bend their knees into more comfortable positions when they experience pain and effusion, even if full extension of the knee was achieved at the time of surgery.

We must also consider clinical evaluation, serological investigation, diagnostic imaging, and microbiological analysis of patients with painful TKA. It is not always possible to diagnose the underlying problem, but it is very important to treat the patient’s pain, especially in the early stages to avoid the development of chronic pain and associated stiffness. The management of painful TKA often requires a multidisciplinary approach including surgeons, physiotherapists, occupational therapists, specialist pain management teams, and the patient’s general practitioner ².

There are limitations to this study. First, ROM was obtained with a goniometer. Though it can be argued that measurements obtained with other methods, such as gait analysis or fluoroscopy which can be more precise, Gogia et al. ²¹ found that goniometric measurements of the knee are both reliable and valid. Second, although we stated that full extension was obtained at the time of surgery, we do not have any objective data such as formal intra-operative measurements or radiographs to support this statement. Third, the small number of patients considered does not allow us to have a sufficiently objective assessment. Fourth, there is no long-term follow-up. However, the incidence and natural history of a newly developed flexion contracture in patients after TKA has not been extensively studied ⁴,²².

Conclusions

The causes of stiffness in knee flexion are often unclear even if the surgeon obtains full extension intra-operatively. We believe that there is a direct correlation with the pain and stiffness seen in the attitude of knee flexion that the patient commonly assumes in the case of pain, and since in our study this shows an improvement in both pain and stiffness with OMT we believe this may be beneficial to allow early rehabilitation.

Conflict of interest statement

The authors declare no conflict of interest.

Funding

This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

Author contributions

AB: conceived of the presented idea, designed the model and the computational framework and analysed the data, investigated and supervised the findings of this work); AT, ATU: investigated the data - manipulations; CR: helped supervised the project; FN: wrote the manuscript with support from AB; MN: helped supervise the project; VS: supervised the project. All authors read and approved the final version of the manuscript.

Ethical consideration

This study was authorized by the Board of Directors of ASL 2 Abruzzo as it is part of “ Osteopathy in Orthopedics” project.

The research was conducted ethically, with all study procedures being performed in accordance with the requirements of the World Medical Association’s Declaration of Helsinki.

All patients were enrolled voluntarily.

Figures and tables

References

1. Goudie ST, Deakin AH, Ahmad A. Flexion contracture following primary total knee arthroplasty: risk factors and outcomes. Orthopedics. 2011; 34:E855-E859. DOI
2. Scranton PE. Management of knee pain and stiffness after total knee arthroplasty. J Arthroplasty. 2001; 16:428-435. DOI
3. McPherson EJ, Cushner FD, Schiff CF. Natural history of uncorrected flexion contractures following total knee arthroplasty. J Arthroplasty. 1994; 9:499-502.
4. Quah C, Swamy G, Lewis J. Fixed flexion deformity following total knee arthroplasty. A prospective study of the natural history. Knee. 2012; 19:519-521. DOI
5. Fehring TK, Odum SM, Griffin WL. Surgical treatment of flexion contractures after total knee arthroplasty. J Arthroplasty. 2007; 22:62-66. DOI
6. Walton NP, Jahromi I, Dobson PJ. Arthrofibrosis following total knee replacement; does ttherapeutic warfarin make a difference?. Knee. 2005; 12:103-106. DOI
7. Lam LO, Swift S, Shakespeare D. Fixed flexion deformity and flexion after knee arthroplasty. What happens in the first 12 months after surgery and can a poor outcome be predicted?. Knee. 2003; 10:181.
8. Fernandez A, Sappey-Marinier E, Shatrov J. Pre-operative flexion contracture does not affect outcome in total knee arthroplasty: a case-control study of 2,634 TKAs. Orthop Traumatol Surg Res. 2023;103592. DOI
9. Archunan M, Swamy G, Ramasamy A. Stiffness after total knee arthroplasty: prevalence and treatment outcome. Cureus. 2021; 13:E18271. DOI
10. Ritter MA, Lutgring JD, Davis KE. The role of flexion contracture on outcomes in primary total knee arthroplasty. J Arthroplasty. 2007; 22:1092-1096.
11. Cheng K, Ridley D, Bird J. Patients with fixed flexion deformity after total knee arthroplasty do just as well as those without: ten-years prospective data. Int Orthop. 2009;14.
12. Mitsuyasu H, Matsuda S, Miura H. Flexion contracture persists if the contracture is more than 15° at 3 months after total knee arthroplasty. J Arthroplasty. 2011;26.
13. Haas SB, Cook S, Beksac B. Minimally invasive total knee replacement through a mini midvastus approach: a comparative study. Clin Orthop Relat Res. 2004; 428:68-73.
14. Hollister AM, Jatana S, Singh AK. The axes of rotation of the knee. Clin Orthop Relat Res. 1993; 290:259-268.
15. Whiteside LA. Soft tissue balancing: the knee. J Arthroplasty. 2002; 17:23-27.
16. Leibger RL. Orthopaedic basic science foundations of clinical practice. AAOS 2007: Rosemont, IL.
17. Aderinto J, Brenkel IJ, Chan P. Natural history of fixed flexion deformity following total knee replacement: a prospective five-year study. J Bone Joint Surg Br. 2005; 87:934.
18. Anania A, Abdel MP, Lee Y-Y. The natural history of a newly developed flexion contracture following primary total knee arthroplasty. Int Orthop. 2013; 37:1917-1923.
19. Tew M, Foster IW. Effect of knee replacement on fl exion deformity. J Bone Joint Surg Br. 1987; 69:395-399.
20. Harato K, Nagura T, Matsumoto H. Flexion contracture will lead to mechanical overload in both limbs: a simulation study using gait analysis. Knee Dec. 2008; 15:467-72. DOI
21. Gogia PP, Braatz JH, Rose SJ. Reliability and validity of goniometric measurements at the knee. Phys Ther. 1987; 67:192-195.
22. Aderinto J, Brenkel IJ, Chan P. Natural history of fixed flexion deformity following total knee replacement: a prospective five-year study. J Bone Joint Surg Br. 1985; 87:934-936. DOI
23. Mitsuyasu H, Matsuda S, Miura H. Flexion contracture persists if the contracture is more than 15° at 3 months after total knee arthroplasty. J Arthroplasty. 2011;26.
24. Cheng K, Ridley D, Bird J. Patients with fixed flexion deformity after total knee arthroplasty do just as well as those without: ten-years prospective data. Int Orthop. 2009;14.