A rare complication of total knee arthroplasty: Type l complex regional pain syndrome of the foot and ankle

Complex regional pain syndrome after multiple revision total hip arthroplasty surgeries

Background

Persistent pain after total hip arthroplasty (THA) is a real concern for the surgeon and is a significant cause of patient dissatisfaction; periprosthetic joint infection (PJI), aseptic loosening, and instability are among the common causes of painful THA. However, few rare causes have been reported in the literature; the complex regional pain syndrome (CRPS) was reported to occur after primary hip and knee arthroplasties. Case presentation: We present a female patient who had bilateral hip resurfacing when she was 28 years old after being diagnosed with bilateral hip avascular necrosis; over 16 years, she was satisfied. She started developing pain in her right hip in 2019, diagnosed as aseptic loosening, and a revision using a cementless THA was performed. Six months later, she was diagnosed with PJI, which was treated in two stages; after the first-stage revision THA, the patient complained of persistent pain in her lower leg with a burning sensation and change in skin color, not responding to conservative lines. During the second-stage revision THA and after receiving spinal anesthesia, the skin color of the right lower limb changed to normal. The postoperative diagnosis was made as CRPS, treated effectively with sympathetic block. At six months postoperative, the patient was pain-free, and the implants showed proper position. Conclusions: Although rare, CRPS could cause persistent pain after repeated hip surgeries, and the diagnosis is reached mainly by exclusion.

A Retrospective Study of the Risk Factors for Postoperative Foot or Ankle Pain in 90 Patients with Varus Osteoarthritis of the Knee who Underwent Total Knee Arthroplasty

Background

The reasons for foot and ankle pain following total knee arthroplasty (TKA) for knee varus osteoarthritis are unknown. This retrospective study aimed to investigate the risk factors for postoperative foot and ankle pain in patients with varus osteoarthritis of the knee who underwent TKA.

Material/Methods

We enrolled 90 patients who underwent TKA for varus knee osteoarthritis. The visual analog scale (VAS) was used to evaluate patients’ foot or ankle pain before and after surgery. The correlation between independent variables (eg, age, sex, body mass index [BMI], ankle osteoarthritis, and varus angle) and foot and ankle pain in patients with osteoarthritis of the knee was measured. Moreover, radiological changes were compared between the groups with and without worsened pain.

Results

No significant difference in VAS was found between patients <60 and ≥60 years of age (P>0.05). Male sex and BMI <30 kg/m² were weakly correlated with preoperative foot or ankle pain. However, patients with varus of ≥6° and preexisting ankle osteoarthritis had a higher incidence of foot or ankle pain before surgery. Moreover, no significant differences in radiological changes were found between the groups with and without worsened foot or ankle pain after surgery (P>0.05).

Conclusions

In male patients with osteoarthritis of the knee, a BMI <30 kg/m², varus of <6°, and no preexisting ankle osteoarthritis were protective factors for foot and ankle pain. TKA corrected knee and ankle malalignment. Therefore, postoperative foot and ankle pain was not associated only with TKA surgery.

A rare cause of type 1 complex regional pain syndrome: Osteoblastoma of the talus

We report a 14-year-old boy who presented with pain in the left foot and ankle for about 9 months. The clinical symptoms of the patient suggested complex regional pain syndrome (CRPS). The radiographs and magnetic resonance imaging studies ravealed a bone tumor in the talus, consistent with an osteoblastoma. The patient underwent operative treatment with curettage and grafting. The complaints of the patient completely resolved by 6 months after surgery, and there was no recurrence at the postoperative 23th month follow-up.