Intra-articular osteotomies for medial compartment osteoarthritis: Is adding an extra-articular osteotomy worthwhile?

Aditya P Apte; Ravi Bhadiyadra; Milind Chaudhary

doi:10.4103/jllr.jllr_16_22

ORIGINAL ARTICLE

Year : 2022 | Volume : 8 | Issue : 1 | Page : 17-23

Intra-articular osteotomies for medial compartment osteoarthritis: Is adding an extra-articular osteotomy worthwhile?

Aditya P Apte, Ravi Bhadiyadra, Milind Chaudhary
Centre for Ilizarov Techniques in India, Akola, Maharashtra, India

Date of Submission	04-May-2022
Date of Decision	21-May-2022
Date of Acceptance	21-May-2022
Date of Web Publication	30-Jun-2022

Correspondence Address:
Milind Chaudhary
Centre for Ilizarov Techniques in India, Chaudhary Hospital, Civil Lines, Akola - 444 001, Maharashtra
India

Source of Support: None, Conflict of Interest: None

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DOI: 10.4103/jllr.jllr_16_22

Abstract

Background and Aims: Medial compartment osteoarthritis (MCOA) of the knee presents with varus deformity arising from the upper tibia or lower femur. High tibial osteotomies relieve pain by correcting the varus and improving the mechanical axis deviation (MAD). Closing wedge, opening wedge, and dome osteotomies are popular choices in the upper tibial metaphysis. These are all extra-articular osteotomies (EAO). Recently, attention has turned to detection and treatment of intra articular deformity arising from the knee to treat MCOA. Tibial condylar valgus osteotomy (TCVO) is an intra-articular osteotomy (IAO) which corrects the varus malalignment by elevating the medial tibial condyle and is usually fixed with a plate (Tibial condylar valgus osteotomy-plating [TCVO-P]). A second distal extra articular osteotomy, fixed with an Ilizarov fixator (tibial condylar valgus osteotomy-Ilizarov [TCVO-I]) is performed in some patients for better correction of the mechanical axis. The two groups were treated with different surgical approaches based on preoperative analysis of deformity. Hence this is a level IV study. We aimed to study the improvement in radiological parameters after TCVO in MCOA. We also compared the results between TCVO-P and TCVO-I. Patients and Methods: We performed 64 osteotomies in 55 patients over the last 7 years. 30 (33 tibiae) had a TCVO-P. 25 (31 tibiae) had a TCVO-I. The mean age in TCVO-P was 55 years, and in TCVO-I was 48 years. Results: The mean preoperative (bo) MAD was more in TCVO-I at –37.4% and improved to a mean postoperative MAD of 53.8%. TCVO-P had a lesser mean bo MAD of –7.4%, which corrected to 46.4%. MAD was better corrected by TCVO-I (P = 0.0058). Correction of medial proximal tibial angle, hip knee ankle angle, ankle joint line orientation improved significantly in both groups. The knee joint line orientation was improved by TCVO-I (P = 0.001), but not by TCVO-P (P = 0.075). Joint line convergence angle (JLCA), spine edge angle, and spine vertical distance were all significantly improved in both groups. Condylar plateau angle was not changed significantly in either group. Conclusion: TCVO is an Intra articular osteotomy which effectively corrects the varus deformity arising from the knee joint in MCOA. An isolated TCVO-P slightly under-corrects the mechanical axis. TCVO-I is better at restoring mechanical axis to beyond neutral and is better for younger patients and with intorsion deformities.

Keywords: Ilizarov, intra articular osteotomy, mechanical axis deviation, tibial condylar valgus osteotomy

How to cite this article:
Apte AP, Bhadiyadra R, Chaudhary M. Intra-articular osteotomies for medial compartment osteoarthritis: Is adding an extra-articular osteotomy worthwhile?. J Limb Lengthen Reconstr 2022;8:17-23

How to cite this URL:
Apte AP, Bhadiyadra R, Chaudhary M. Intra-articular osteotomies for medial compartment osteoarthritis: Is adding an extra-articular osteotomy worthwhile?. J Limb Lengthen Reconstr [serial online] 2022 [cited 2023 Mar 30];8:17-23. Available from: https://www.jlimblengthrecon.org/text.asp?2022/8/1/17/349414

Introduction

Medial compartment osteoarthritis (MCOA) presents with varus deformities in the lower limb. Correcting the varus deformity helps treat MCOA. High tibial osteotomies performed in the upper tibial metaphysis correct the varus and relieve pain. Common osteotomies are closing wedge,^[1] open wedge,^[2],[3] a convex upward dome, or a convex downward focal dome.^{[4],[5],[6],[7]} All give good correction and relief of pain. Since 2003, Babis et al.^[8] and Nakayama et al.^[9] have described a double osteotomy to correct the varus in the lower femur and upper tibia, which helps fully correct large mechanical axis deviations (MADs) without changing knee joint line orientation (KJLO).

The role of intra-articular deformity in the knee joint contributing to MCOA have recently been elaborated.^{[9],[10],[11]} On clinical examination, increased mediolateral laxity of the knee with a dynamic varus on walking point toward an intra-articular deformity. Joint line convergence angle (JLCA) and condylar plateau angle (CPA) help confirm the intra-articular deformity on X-rays. Spine edge angle (SEA) and spine vertical distance (SVD) help monitor the changes in intra-articular deformity parameters.^[10] The tibial condylar valgus osteotomy (TCVO), an intra-articular osteotomy, corrects the deformity based on these clinical and radiological parameters.^{[11],[12],[13],[14]}

Paley explained how best to choose the ideal osteotomy for each deformity.^[15] A recent update^[16] classifies the deformities in MCOA as Primary (varus), Secondary (intra-articular), and Tertiary (sagittal, axial, and rotational deformities). Opening or closing wedge osteotomies can correct mild-to-moderate primary varus deformities. The focal dome osteotomy fixed either by the Ilizarov Fixator or a locking plate can best correct large extra-articular varus accompanied by Tertiary deformities. TCVO corrects varus deformities with an Intra-articular component. A double tibial osteotomy (one intra-articular and a second distal extra-articular), fixed with an Ilizarov fixator^[16] (TCVO-I), better corrects large varus deformities with a combination of intra-articular, extra-articular, and tertiary components in sagittal, axial, and rotational planes.

Intra-articular deformities are also present in Blount's Disease with severe depression of the medial tibial condyle. Hemi-plateau elevation is an accepted method of treatment.^[17] It may, however, not be enough to correct the overall varus alignment. Here too, a second diaphyseal tibia osteotomy performed below the hemi-plateau elevation fixed using an Ilizarov fixator helps correct both the intra- and extra-articular deformity.

We have performed intra-articular osteotomies since 2014 and aim to describe their radiological correction and early complications. We also compare results in patients who had only an isolated intra-articular osteotomy fixed with a plate (tibial condylar valgus osteotomy-plating [TCVO-P]) and those who had a double intra- and extra-articular osteotomy, fixed with an Ilizarov fixator (tibial condylar valgus osteotomy-Ilizarov [TCVO-I]).

Patients and Methods

We have performed 64 intra-articular osteotomies in 55 patients suffering from MCOA in our institute since 2014. There were 38 Right and 26 left limbs. Sixteen were male and 39 females [Table 1]. We took informed consent and institutional review board approval for this retrospective study of radiological measurements done on full-length X-rays. We also performed a chart review to note any complications during and after treatment. We did statistical analysis of the data using MS-Excel. We used the t-test to compute the comparison of means. We considered P < 0.05 as statistically significant.

Table 1: Demographic data

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We performed isolated intra-articular osteotomies fixed with a plate (TCVO-P) on 33 tibiae in thirty patients [Table 2]. We performed combined intra- and extra-articular osteotomies fixed with an Ilizarov fixator (TCVO-I) [Table 3] in 25 patients on 31 tibiae. Twenty of 31 tibiae had an intorsion deformity which we measured clinically. We did not perform any computed tomography scans.

Table 2: Alignment - Deformity parameters of tibial condylar valgus osteotomy-plating

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Table 3: Alignment - Deformity parameters of tibial condylar valgus osteotomy-Ilizarov

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The two groups were treated with different surgical approaches based on preoperative analysis of deformity. It was not a comparison of two groups to see which treatment is superior. The choice between two osteotomy types was algorithmic and based on the severity of varus deformity and additional deformities like tibial intorsion. Hence, this is a level IV study.

Medial proximal tibial angle (MPTA), mechanical lateral distal femoral angle (mLDFA), hip knee ankle angle (HKA), KJLO, and ankle joint line orientation (AJLO) were measured in all patients pre- and post-operatively (bo, po). Intra-articular deformity parameters, JLCA, CPA, SEA, and SVD were also calculated and analyzed before and after surgery.

Surgical technique

Isolated intra-articular osteotomy fixed with a locking plate (tibial condylar valgus osteotomy-plating)

The need for intra-articular osteotomies (IAO) was determined by clinical features like increased mediolateral laxity on examination and dynamic varus on gait. We used radiological measurements of CPA, JLCA, SEA, and SVD to measure the presence of intra-articular deformities and their changes after surgery. We chose this osteotomy for MAD > –10%.

After regional anesthesia and under tourniquet control, we checked and recorded mediolateral, anteroposterior, and rotational laxity under the C-arm. We took a vertical midline incision and a performed a patellar retinacular release^[18] in all patients, as all had patellofemoral pain. We released the pes anserinus and exposed the tibia medially and posteriorly, sub-periosteally. All osteotomies had two limbs: One vertical, running medial to the patellar ligament ascending upwards from the lower end of tibial tuberosity to medial tibial spine. The second, a horizontal or oblique limb from distal end of the vertical cut going medially. We marked the posterior cortex of both these cuts with K-wires and small drill bits and then completed the posterior cortex osteotomy cut with a thin sharp osteotome under C arm control in the lateral view. We carefully cut the intra-articular portion between the tibial spines by monitoring with the C arm in the lateral view.

We inserted two thin K-wires, one from the medial and one from the lateral side in the subchondral bone and fixed with the stoppers at the medial and lateral cortex to prevent spreading of the condyles. A gentle valgus force was applied, an arthrodesis spreader used to open the osteotomy and the correction checked with either an alignment rod or a radiolucent grid.

The endpoint of correction is determined by the reduction of the mediolateral laxity, which comes before the correction of mechanical axis through the Fujisawa point. We wait a while to allow the creep property in ligaments to permit yet more correction with the spreader. We checked reduced mediolateral, and laxity in other directions under the C-arm. We finally fix the osteotomy with a locking plate [Figure 1]a,[Figure 1]b,[Figure 1]c. We closed the wound over a drain.

Figure 1: (a) Preoperative full-length X-ray of a 63-year-old female with right MCOA, MAD is at 26%. (b) Preoperative right knee AP X-ray showing TCVO with medial tibial plating. (c) Postoperative full-length X-ray, right lower limb MAD is at 55%. MCOA: Medial compartment osteoarthritis, MAD: Mechanical axis deviation, TCVO: Tibial condylar valgus osteotomy, AP: anteroposterior view

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Double intra plus extra-articular osteotomy (tibial condylar valgus osteotomy-I)

We used TCVO-I for large varus deformities with preoperative MAD (bo MAD) <–10%.^{[6],[13],[16]} Since most isolated intra-articular osteotomies are unable to shift the mechanical axis beyond 50%, combined intra- and extra-articular osteotomies are better. We performed the intra-articular component exactly as above, and after eliminating mediolateral laxity, fixed the osteotomy with cancellous screws or half pins which cross the vertical limb of the osteotomy.

We inserted two vertical thin tapered half pins just distal to the end of this osteotomy. We attached all these half pins to a single proximal ring with rancho cubes, hinges, and other Ilizarov components. We performed a fibulectomy at the upper or middle third level.

We outlined a curved, distally convex dome osteotomy with drill holes about an inch below the lower end of the upper osteotomy. We created a distal block of fixation with two rings, 15 cm apart, and fixed with one-half pin in each ring. We completed the dome osteotomy with an osteotome and translated the distal fragment laterally by one cortex width and angulated it out of varus, enough to correct the mechanical axis to around the Fujisawa point. We connect the upper and middle rings with multiplane hinges and fine-tune the correction over 2 weeks after the surgery [Figure 2]a,[Figure 2]b,[Figure 2]c,[Figure 2]d,[Figure 2]e.

Figure 2: (a) Large varus deformity with significant MAD. (b) Fibulectomy done. L-shaped osteotomy outlined at the level of medial tibial spine. (c) L-shaped osteotomy opened and fixed with crossing half pins. Lower pins inserted the second osteotomy outlined. (d) Lower osteotomy laterally translated and corrected to the desired extent. (e) Full correction of mechanical axis and IA deformity. MAD: Mechanical axis deviation

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When the patient could stand upright for a full-length X-ray, the MAD was recorded and the correction was altered as needed. The final MAD was calculated after Ilizarov removal. Most patients could resume activities of daily living in a few weeks and resume their employment in 4–6 weeks. The fixator usually came off in 14–18 weeks [Figure 3]a,[Figure 3]b,[Figure 3]c,[Figure 3]d.

Figure 3: (a) Preoperative full-length X-ray of a 65-year-old female with Left MCOA, MAD is at-50%. (b) Preoperative left knee AP X-ray showing intra-articular osteotomy fixed with screws and the extra-articular osteotomy fixed with an Ilizarov ring fixator. (c) Preoperative full-length X-ray, left lower limb MAD is at 57%. (d) Preoperative full-length X-ray after Ilizarov removal. MCOA: Medial compartment osteoarthritis, AP: anteroposterior view

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Results

TCVO-P improved the mean MAD from a bo –7.4% to po of 46.4% of the knee joint width. MPTA, HKA, and AJLO changed significantly. Knee joint line orientation (KJLO) did not change after TCVO-P (P = 0.075). mLDFA, as expected, did not change [Table 2]. Mean Δ MAD (amount of correction of MAD) was 53.7%.

In the TCVO-I group, the mean MAD changed from -37.4% to 53.8%. Changes in HKA, MPTA, KJLO, and AJLO were all significant. mLDFA did not change [Table 3]. Mean Δ MAD was 89.1%.

The difference between Δ MAD in TCVO-P and TCVO–I was significant (P = 0.01).

We have recorded intra-articular deformity parameters and their change, as shown in [Table 4] and [Table 5]. JLCA, SEA, and SVD changed significantly in both osteotomy groups. There was no significant change in CPA in either group (P values: TCVO-P = 0.13, TCVO-I = 0.65).

Table 4: Intraarticular deformity parameters of tibial condylar valgus osteotomy-plating

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Table 5: Intraarticular deformity parameters of tibial condylar valgus osteotomy-Ilizarov

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Complications

Deep infection developed in three patients with TCVO-P and needed implant removal after osteotomy union, without loss of correction and further incident. We noted allergic skin reactions near the operative wound in four which but did not affect the result. There were more complications in patients who had TCVO-I. Two patients had one distal and proximal pin tract infection each needing debridement and sequestrectomy. Another developed a fracture after implant removal through the distal osteotomy which healed in a cast but resulted in knee stiffness. A 65-year-old fell from the bed immediately after the surgery and sustained an avulsion fracture of the tibial tuberosity. We treated him by an extension cast above the knee but he lost 60° of flexion. One patient developed deep vein thrombosis which we controlled with medical treatment. She also had an EHL paralysis which has not recovered to date.

Discussion

Extra-articular high tibial osteotomies are a dependable nonarthroplasty treatment for MCOA. Closing wedge, opening wedge, proximal supra tuberosity dome, and distal infra tubercle focal dome osteotomies are all popular and successful. Babis et al.^[7] and Nakayama et al.^[8] highlighted the role of extra-articular double osteotomies in the distal femur and proximal tibia to maintain knee joint line orientation and achieve full correction of the mechanical axis.

Chiba^[10],[14] described and used intra-articular osteotomies of the upper tibia since 1989 in Japan. Their role is only recently being appreciated.^[12] We came to know of TCVO from Teramoto^[11] in 2014 and have used it since then. We now know how to diagnose intra-articular deformities causing MCOA by clinical and radiographic examination. Clinical signs include a large varus deformity, increased mediolateral laxity, and a dynamic varus gait. An increased JLCA and CPA help verify the presence of intra-articular deformity on X-rays [Table 4] and [Table 5]. There is also a moderately high correlation between MAD < 0% and an increased CPA.^[13] Hence, patients with a large MAD and a severe varus could have an intra-articular deformity. We report our satisfactory correction of deformity parameters with the intraarticular osteotomy and discuss TCVO-I,^{[6],[10],[13],[16]} a newer double tibial osteotomy which better corrects the overall mechanical axis.

Extra-articular osteotomies (EAO) rely on correction of alignment to offer pain relief. Heijens theory can explain the mechanism of pain relief in EAO in the presence of undetected intra-articular deformities by the coronal hypomochlion.^[19] Correction of the HKA to 2° valgus is enough to shift loading away from the medial compartment, regardless of the presence of an intra-articular deformity.

IAO gives pain relief by improving congruent contact between the medial and lateral tibiofemoral condyles. The resulting larger weight-bearing area reduces point loading in the medial compartment. The elevation of the edges of the condyles as measured by SEA and the decreased SVD which measures the lowering of intercondylar eminence, mildly stretches, and stabilizes the cruciate ligaments.^[11] CPA did not change significantly in either TCVO-P or TCVO-I [Table 4] and [Table 5]. We have previously described the difficulties in measuring CPA accurately. SEA and SVD may not be diagnostic of an intra-articular deformity but accurately measure the change before and after surgery^[10] [Table 4] and [Table 5].

TCVO-P patients had a slightly undercorrected MAD, [mean po = 46.3%, [Table 2]] compared to the Fujisawa point.^[20] However, the mechanism of pain relief in IAO is not just correction of overall limb alignment, but also improvement of joint congruity and improved joint stability. Better congruity of the joint is evident by the reduced JLCA and reduced mediolateral laxity. We evaluated improved stability of the joint on the table by reduced abnormal mobility of the joint in mediolateral, anteroposterior, and rotational movements, measured before and after surgery by image intensifier.

While most patients have adequate pain relief, we cannot ascertain the longevity of results since our maximum follow-up is only 90 months (mean 66 months, range 24–90 months). To ensure the longevity of results, we chose to achieve better correction of the mechanical axis by a double osteotomy in the tibia in 25 of our patients by TCVO-I. Here, the distal extra-articular osteotomy ensured adequate correction of the mechanical axis [mean po MAD = 53.8%, [Table 3]].

AJLO was significantly in varus in TCVO-P (8.5°) and TCVO-I (14.5°) and improved significantly to –0.3° and –2.9° (valgus), respectively. KJLO was near normal preoperatively (TCVO-P = 2.5°, TCVO-I = 5.5°) and did not change with TCVO-P (0.9°) but improved with TCVO-I to 0.16° [Table 2] and [Table 3]. The change (Δ) in MAD, HKA, MPTA, KJLO, AJLO [Table 6] is significantly more in TCVO-I. The change (Δ) in JLCA, CPA, SEA, SVD is the same between TCVO-P and TCVO-I. This is as expected since the latter parameters reflect changes caused by the intra-articular osteotomy which was identical in both the groups [Table 7].

Table 6: Change (Δ) in alignment - Deformity parameters

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Table 7: Change (Δ) in intra-articular deformity parameters

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Hence, while TCVO-I was better at correcting the overall alignment parameters it came with the price tag of a longer and complex surgery, and some complications. These patients also had to wear a fixator for 14–18 weeks. The mean age of patients in the TCVO-I group was significantly lesser at 48 years (P = 0.02) than TCVO-P at 55 years. Hence, we used TCVO-I in younger patients with a larger varus deformity. Twenty of our patients had correction of severe tibial intorsion through the second EAO of TCVO-I.

The following criteria help decide the need for a second osteotomy. First, TCVO-P passes through the medial tibial spine, medial to patellar ligament. Hence, it did not correct the MAD to neutral or beyond to the Fujisawa point. To better correct the mechanical axis and give a better chance of longevity of results, a second osteotomy can help. Second criteria would be the presence of a large intorsion deformity only correctible through a second osteotomy. Third, Kuwashima et al.^[21] created this equation to help decide the need for second osteotomy. Consider α = angle needed to achieve correction of MAD to Fujisawa point. Angle vr (+) is the JLCA in a varus stress X-ray. Angle vl (-) is the JLCA in valgus stress X-ray. β = (vr + vl) x 1.5. If α> β, then a second osteotomy is required.

The limitation of our study is that we do not have patient-reported outcome measures. The two groups are not equally matched. There is not adequate English literature describing these intra-articular osteotomies and the concept and performance of these osteotomies may not be acceptable to all. With a longer follow-up we will be able to ascertain the utility of these osteotomies, especially TCVO-I. The exact role of alignment using EAO, and improved joint congruity achieved by IAO in achieving long-term pain relief is yet unproved. The pertinent question to answer would be: Is it possible to combine the two osteotomies in one? Igarashi et al.^[22] in a recent study have described the focal dome condylar osteotomy (FDCO) which does just that. In FDCO, the vertical limb of the osteotomy is lateral to the patellar ligament as opposed to medial in TCVO. Its entry into the joint coincides with the lateral tibial spine which is at approximately 60% of joint width. Hence, it may achieve full correction of the mechanical axis through a single osteotomy. If FDCO lives up to its promise, the indications for TCVO-I may reduce.

Conclusion

Intra-articular deformities of the knee joint contributing to MCOA have recently been elaborated. The TCVO fixed with a locking plate (TCVO-P) corrects the intra-articular deformity, improves joint congruity to give pain relief, but does not correct the mechanical axis beyond 50%. Adding a second distal diaphyseal extra-articular dome osteotomy beneath the TCVO, fixed with an Ilizarov fixator, corrects the intra-articular deformity, and corrects the MAD beyond 50%. Improved alignment with the TCVO-I however comes at the cost of wearing a fixator and minor complications. A longer follow-up may reveal if the additional osteotomy and better correction of the mechanical axis improves clinical results.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

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