Total knee arthroplasty is performed to provide pain relief, joint stability and a satisfactory range of motion. It has been estimated that a minimum of 90° of range of motion in the knee is required for activities of daily living. 65° of knee flexion is required in the swing phase of normal gait and 106° of flexion is needed to arise from a chair easily or tie shoe laces [1].

Disabling stiffness after total knee arthroplasty (TKA) is rare, but can be devastating for the patient. Most patients complain of pain and diminished function associated with the stiffness. The true prevalence is unclear due to the lack of an established definition [2]. Several studies have attempted to define factors that have significant effect on range of motion (ROM) after TKA and most have shown that preoperative ROM is the principal predictive factor of postoperative ROM [3, 4]. Other factors include removal of posterior osteophytes and release of the deep medial collateral ligament in patients with large preoperative varus alignment [3].

Extrinsic sources of knee stiffness must be excluded (e.g. osteoarthritis of the ipsilateral knee, neurological injury leading to muscle rigidity or heterotopic ossification). When such problems exist, revision surgery is unlikely to be successful until they have been addressed.

With the exclusion of extrinsic aetiologies, the objective is to identify specific intrinsic causes that are amenable to surgery (see Table 1) [5]. Of these, arthrofibrosis is one of the most unresponsive causes. Arthrofibrosis is an abnormal proliferation of fibrous tissue in and around a joint that can lead to loss of motion. It is thought to result from pathological tissue hyperplasia following injury or surgery to the knee [6]. The knee is particularly vulnerable and widespread fibrous tissue can lead to altered knee biomechanics. Care needs to be taken when patients are on warfarin after TKA as the relative risk of developing stiffness due to arthrofibrosis postoperatively is 3.7 times greater than in unwarfarinised patients [7].

There were 2 females (aged 62 and 84) and one male (age 59). The mean interval between the primary and secondary surgery was 17.7 months (range 14 to 20). A summary of the procedure and range of motion for each patient is summarised in Table 2. The mean increase in flexion after revision surgery was 60 degrees (55, 60, and 65) with all patients reporting an improvement in pain, mobility, and activities of daily living.

Though there is no consensus about timing, manipulation under anaesthesia is usually the first step in the management of stiff TKA [1, 2, 6, 7]. This procedure is usually undertaken within 2 months of primary surgery. If ROM does not improve or even regress and all other intrinsic causes of stiffness have been excluded, then several operative options are available but there is no established operation for an arthrofibrotic stiff knee following TKA. Yercan et al. [2]. performed secondary surgery on 10 patients (3 arthroscopic debridements, 5 open arthrolysis and 2 component revisions). In the arthrotomy group, the ROM improved from a mean of 66 degrees preoperatively to 107 degrees (an improvement of 41 degrees) postoperatively. This group also included 2 patients that had patellar “clunk syndrome”. If these were excluded from this group then simple arthrolysis resulting in improved ROM resulted in only one of three patients. These results are supported in another study in which seven knees with stiffness post TKA were treated with arthrolysis and conversion to a thinner tibial polyethylene insert [9]. Two knees required revision for aseptic loosening and infection. All five of the remaining knees were painful and stiff (four severely painful) at the time of final follow up. Our results compare favourably with these two studies. All three of our patients reported a marked improvement in pain whilst also maintaining a mean increase in flexion of 60 degrees. We believe that lengthening the extensor mechanism by performing the V to Y quadricepsplasty is the main reason for the difference in results.

In Papagelopoulos’s series of 42 stiff knees following TKA, quadricepsplasty combined with arthrolysis was performed in 6 cases of severe joint ankylosis. In 3 cases the Judet quadricepsplasty technique was performed and in 2 the modified Coonse and Adams quadricepsplasty [1]. Though no further operative treatment was performed, the average range of motion at last follow up was only 55° (range 20°-80°). Furthermore, in this series intra-articular arthrolysis was performed in a separate cohort of 18 knees. In all cases although there was an initial increase in ROM, this was not consistently maintained. This paper highlights the point that simple arthrolysis does not result in good functional outcome in the long term. The mean range of motion in our series improved from 46.7° to 106.7°. This is a substantial difference compared to Papagelopoulos’s series and this could be due to the fact that all 3 patients in our study had excision of the PCL and in one patient the polyethylene insert was changed to a thinner component. This patient had the greatest increase in flexion and ROM.

The use of quadricepsplasty to increase knee flexion is not a new concept. Nicoll [8] and Thompson [10] described a technique (which leaves most of the quadriceps mechanism detached from the patella) and reported satisfactory results following femoral shaft fractures. Judet’s treatment for quadriceps contracture involved detaching the vastus lateralis and medialis from the entire length of the femur [11]. A more recent study has confirmed the effectiveness of this procedure in native stiff knees following trauma [12]. These techniques are not easily applicable to patients with total knee replacements, where the primary surgical site is at the knee, and where an intact extensor mechanism with a sealed joint is desirable. However, a modified V-Y quadricepsplasty procedure has been described to facilitate greater exposure during total knee replacement in the ankylosed knee [11]. In Scott et al.’s series of 7 patients using the same technique, the average improvement in flexion was 49 degrees [11]. Our mean increase in flexion was 60 degrees and though a different cohort of patients, compares favourably with their study.

In Garvin’s case series of 16 patients, the quadriceps snip was used to assist in the surgical exposure of the knee [13]. This technique is essentially a modification of Coonse and Adams operative approach to the stiff, ankylosed or revised knee joint. Eight patients had previous knee prostheses and were undergoing revision surgery for aseptic loosening. The range of motion was increased by 30 degrees on average, though there was significant weakness in extension of the knee when compared with the contralateral side. Our results are more promising with respect to improving knee flexion whilst maintaining extension.

Rodriguez Blanco et al. reported an endoscopic quadricepsplasty technique in 26 patients suffering from knee stiffness from a variety of causes (4 of which were post operative) [14]. Their intra- and extra-articular techniques resulted in 65% of patients gaining at least 70 degrees of flexion at 3 months follow up. This is similar to our findings in which the mean improvement in flexion (at a minimum follow up of 3 months) was 60 degrees.

To our knowledge, the detailed technique we present here has not been reported previously with regards to improving knee stiffness post total knee replacement.

The value of the procedure described in relieving stiffness is that revision surgery (a major procedure with serious complications) is not required. This is the only known soft tissue procedure described for stiffness after total knee replacement. Previously simple arthrolysis with or without change of tibial insert has met with limited success [2, 9].

When a posterior cruciate ligament – preserving knee design is utilised, limited flexion may result if the PCL is too tight. Williams et al. reported an average increase in flexion of 40.1 degrees after arthroscopic release of the PCL in such patients [15]. Although all 9 patients reported subjective improvements in pain and stiffness, two eventually required revision arthroplasty. This highlights the importance of performing other soft tissue procedures as well as a PCL release. In all our patients the PCL was excised to further increase flexion and we recommend this as part of the soft tissue procedure, particularly if a PCL retaining prosthesis was used initially. It is necessary to ensure that the soft tissue balance of the TKA is correct otherwise sacrificing the PCL (which leads to an increase in flexion gap) may lead to subluxation or even dislocation of a posterior-stabilised prosthesis [16].

Although all three patients clearly stated a subjective improvement in pain and function as well improvement in knee flexion following this procedure we were unable to demonstrate this objectively as none of the patients had pre-operative functional knee scores.

In conclusion we describe an operation in which a V-Y quadricepsplasty was combined with a defined soft tissue procedure in order to relieve stiffness following total knee arthroplasty. The main indications are pain, functional limitation and stiffness. Additionally, extrinsic sources of knee stiffness should be excluded before performing this procedure and if the aetiology is solely arthrofibrosis then a more favourable outcome is likely to occur (Fig. 4).

Fig. (4). Post V-Y Quadricepsplasty – Knee in flexion (Fig. 4a) and extension (Fig. 4b).