Indian Journal of Orthopaedics

: 2002  |  Volume : 36  |  Issue : 4  |  Page : 234--237

Simultaneous bilateral versus unilateral total knee replacement in osteoarthritic knee

BK Dhaon, V Sharma, A Jaiswal 
 Department of Orthopaedics, Maulana Azad Medical College, New Delhi, India

Correspondence Address:
B K Dhaon
44, Kotla Road, New Delhi - 110002


Ten simultaneous bilateral total knee replacements were compared with ten unilateral total knee replacements in osteoarthritic knee. All procedures were performed using same preoperative, intraoperative and postoperative protocols. Results showed that simultaneous bilateral TKR had higher incidence of medical complications, more requirements of blood transfusion and raised temperature of more than 1000 F for more than 48 hours, although there were advantages of simultaneous bilateral TKR in terms of decreased hospital stay, better utilization of scarce hospital resources, early rehabilitation and no risk of second anesthesia. The true safety and efficacy of simultaneous bilateral TKR needs further evaluation.

How to cite this article:
Dhaon B K, Sharma V, Jaiswal A. Simultaneous bilateral versus unilateral total knee replacement in osteoarthritic knee.Indian J Orthop 2002;36:234-237

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Dhaon B K, Sharma V, Jaiswal A. Simultaneous bilateral versus unilateral total knee replacement in osteoarthritic knee. Indian J Orthop [serial online] 2002 [cited 2019 Sep 23 ];36:234-237
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Bilateral involvement of the knee joint in arthritic pathology is common. Patients with osteoarthrosis of the knee joint usually have bilateral involvement but one side is more symptomatic than the other. Total knee replacement (TKR) is a widely accepted procedure for arthritic knees, as it provides restoration of function and alignment in advanced arthritic changes. The decision to replace bilateral joints in single anesthesia or unilateral replacement is not clear. There are several studies to support the use of simultaneous approach. [1],[2],[3] The chief advantage has been the reduction of total cost, especially in terms of duration of hospital stay, which is approximately 7-20 days less than staged procedures. [1],[2],[4] Outcomes in terms of knee score and radiographic evaluation have been comparable. [2],[3],[4] However different studies have quoted different rates of complications, with some studies quoting simultaneous approach as having less, [3],[5] equal [1],[4] or greater [2] complications than staged procedures. This study was conducted to report our experience of bilateral simultaneous TKR and unilateral TKR in osteoarthritic knees.

 Material and Methods

A prospective study was conducted in 20 patients divided in two groups. Ten patients in first group underwent bilateral simultaneous TKA and 10 patients in second group underwent unilateral TKA for osteoarthritic knees. All patients were operated with similar prosthesis using PCL sacrificing IB - II components and CMW - I bone cement. Tourniquet was used for all cases. For simultaneous cases, the second knee was begun only after the tourniquet was released on the first knee. Drapes were retained in simultaneous procedures.

Before surgery all patients were subjected to a comprehensive medical evaluation. The decision for staged versus simultaneous procedure was made on the basis of patients request and financial considerations.

Epidural anesthesia was used in all 20 patients. All cases were operated under antibiotic cover in routine operating theatres. Same approach was used in all patients. Intramedullary alignment guide was used only on femoral side.

Similar postoperative protocols were followed in both groups. Bulky dressings were removed on 5th postoperative day and patient was put on active physiotherapy for quadriceps and hamstring muscles. Depending on the ability of the patient to actively extend his/her knee, patient was mobilized on a walker by 8-9 day anaesthetic checkup) for preoperative morbidity. Information was also obtained on total tourniquet time, total operative time, intraoperative blood loss, postoperative drainage and total blood replacement. Any other major event including complications was also recorded.


The indication of surgery was osteoarthritis in all patients. Preoperative morbidity on the basis ASA grading was similar in both groups [Table 1]. Total blood loss including drain output was higher in simultaneous groups. One surgical procedure for both knees resulted in a total loss of 1256 ml of blood. Unilateral replacement resulted in loss of 450 ml of blood [Table 2].

Mean tourniquet time per knee was 78.5 min. in simultaneous group and 76 min. in unilateral group. Mean total operating room time was 240 min. in bilateral group and 110 min. in unilateral group. Average need for blood transfusion was 3.2 units in bilateral simultaneous group and 1.1 units in the unilateral group. There were increased complications in simultaneous group. There was higher incidence of patients having temperature > 1000 F for > 48 hrs (6 in bilateral group and only 1 in unilateral group). Urinary catheterization for > 24 hrs was required in 5 patients in bilateral and none in unilateral group. Urinary tract infection was seen in 2 patients in bilateral group and none in unilateral group. Local wound complication was higher in bilateral group. There was delayed wound healing in 2 patients, marginal wound necrosis was seen in 2 patients and haematoma formation was seen in 1 patient. None of these complications were seen in unilateral group. One patient with an old psychiatric illness had 2 episodes of generalized tonic clonic seizures after bilateral procedure and he had to be dilantanized [Table 3].

One patient in the bilateral group had hypovolemic shock leading to pre- renal azotemia. Patient was maintained on dopamine for 2 days and output monitored. He subsequently recovered after medical management. Criteria for Fat embolism syndrome included mental status changes or confusion with associated abnormal arterial blood gas. In no patient did we find any evidence of fat

Data was collected in form of ASA grading (pre- embolism syndrome.

Hospital stay was 16 days in the bilateral group and 13 days in unilateral group. Postoperative knee score improved to 86.5 points in the bilateral group and 93 points in unilateral group on the basis of HSS knee scoring system.


Blood loss was noted to be significantly higher in the bilateral simultaneous group, as compared to the staged group. Average total blood loss in the unilateral knee was 450 ml. In the bilateral simultaneous knee, one knee averaged 628 ml, which was 178 ml more than that in the unilateral group. Most of this was seen in the drain collections during the first 48 hours. Prior studies have demonstrated that hematological changes are associated with simultaneous bilateral TKR, which show a relative thrombocytopenia that peaked on second postoperative day. [6] This change in the clotting mechanism may be the reason for increased loss via the drains.

Increased loss of blood in the simultaneous group was responsible for increased requirements of postoperative blood transfusions. 3.2 units of blood were required for the bilateral group while 1.1 units were required for the unilateral group. This shows an increased requirement of almost one unit of blood when both knees were operated simultaneously than when staged procedures were done with one knee operated at a time. This leads to increased risk of transfusion reactions, clotting abnormalities and infection. Brotherton et al [1] found blood loss same for staged and simultaneous procedures. McLaughlin et al [3] found blood loss to be less in the simultaneous group. However our experience in this study has consistently demonstrated an increased blood loss in the simultaneous bilateral group, which was probably due to altered coagulation cascade.

Total tourniquet time for one knee in the bilateral simultaneous group was 78.5 minutes and it was 76 minutes in the unilateral group. This was almost the same for both groups. This was also reflected in the total operating room time, which was 240 minutes in the simultaneous bilateral group and 220 minutes in the unilateral group, when other knee was operated after some days. Hence, there was no wastage of operating room time in simultaneous group when compared to unilateral group. However this finding differs from other studies. Jankiewicz et al [7] reported significant less time with simultaneous group when compared to staged group. Some advantages of the simultaneous bilateral TKR were single anesthesia, single preoperative workup and single operating room set up.

Average time of hospital stay was 16 days for simultaneous bilateral group and 13 days for unilateral group. Hence, staged procedures required almost 10 days extra, which could be valuable in a busy hospital centre where beds are always scarce.

Complications were significantly greater in the bilateral simultaneous group. Increased temperatures of more than 100 0 F for more than 48 hours was seen in as many as 60% patient in the bilateral group. This was due to increased catabolism seen in bilateral simultaneous group due to greater disturbance in the balanced homeostasis of the body owing to a longer surgical exercise than unilateral group. But this raised temperatures led to increased investigations, frequent wound inspections, longer antibiotic coverage apart from sleepless hours for surgeons.

Urinary catheterization was required for longer time (> 24 hours) in 5 patients in the bilateral group and in none in the unilateral group. This was due to greater difficulty felt in the simultaneous bilateral group in passing urine due to excessive pain on movement of the operated extremities. Unilateral group had no such problems. Increased catheterization rates also lead to higher rates of urinary tract infections in bilateral simultaneous group. Two patients tested positive for UTI. Wound complications were significantly greater in bilateral simultaneous group.

Delayed healing was seen in two patients. Marginal wound necrosis was also seen in two patients. This was probably related to increased requirements of limited amount of blood in bilateral simultaneous group. This lead to deficient wound healing and marginal ischemic necrosis. One patient also developed large haematoma in the subcutaneous plane. This was related to the coagulation disturbance. One patient who had past history of psychiatric illness almost 15 years back suffered from GTCS with psychosis. His ABG was normal, thus ruling out fat embolism. Sudden stress may have precipitated his illness.

One patient went into pre-renal azotemia. This was again due to increased blood loss leading to hypovolumic shock. Patient had to be maintained on dopamine for improving blood pressure and renal output. Electrolyte imbalance and ventricular ectopics due to it were also seen.

Fat embolism has been reported to be consistently low in the literature [8] . Freeman [9] reported only 2 cases of fat embolism syndrome with 80 procedures. Our result demonstrated no case of fat embolism syndrome. This was probably due to enlarged drill hole and fluted rod in the femoral medullary canal. Hence advantages of simultaneous bilateral TKR have been few and far. Low cost in terms of decreased hospital stay, single anesthesia, single operative workup and single operating room set up were the only advantages. Disadvantages were increased blood loss, increased blood requirements, increased complications due to increased loss of blood like ARF, shock and wound necrosis. Also higher postoperative temperature and precipitation of past illness all made simultaneous procedure to be a risky choice. Unilateral staged procedures were good in terms of less morbidity.

Clinical results were equal in both the groups. Hence it appears that unilateral TKR still offers a better choice. The effectiveness of bilateral simultaneous TKR must be studied in a longer group to prove its effectiveness.


1Botherton SL, Roberson JR et al . Staged versus simultaneous bilateral total knee replacement. J Arthroplasty 1986; 1: 221.
2Gradillas EL, Volz RG. Bilateral total knee replacement under one anaesthesia. Clin Orthop 1979; 140 : 153
3McLaughlin, TP, Fisher RL. BilateralTotal knee arthroplasties. Comparison of simultaneous (two team), sequential and staged knee replacements. Clin Orthop 1985; 199: 220.
4Jardaler WT, Ogden WS et al. Simultaneous and staged bilateral total knee arthroplasty. J Bone Joint Surg (Am) 1978; 60-A : 247.
5Soundry M, Binazzi R et al. Successive bilateral total knee replacements. J Bone Joint Surg (Am) 1985; 67-A : 573.
6Stern SH, Sharrock N et al. Hematologic and circulatory changes associated with total knee arthroplasty surgical instrumentation. Clin Orthop 1994; 299:179.
7Jankiewicz JJ, Sculco TP et al. One stage versus 2 stage bilateral total arhtroplasty, Clin Orthop 1994; 309: 94.
8Arden GP. Total knee replacement. Clin Orthop 1993; 294: 92.
9Freeman PA. Walldius arthroplasty. A review of 80 cases Clin Orthop 1973; 94 : 85.