On average male participants resumed driving between the 6th and 7th week post-surgery, female participants resumed driving between the 8th and 9th week post-surgery. This study aided in the verification of the fact that different study sub-groups in part showcase drastically different results. For this reason, recommendations should be individualised as “one size fits all” recommendations are not helpful in this context.
A significant goal of a study participant, with pre-operative regular driving practice, who underwent a TKA or THA procedure, is the swift resumption of driving after surgery. From a therapeutic perspective, this means that patients who wish to drive again shortly after surgery should receive individualised counsel and precise support and training so far as they are part of one of the risk sub-groups mentioned above.
A striking result of the gender analysis of postoperative driving was the binomial distribution of female participants. (Figure 1) Male participants and a proportion of female participants behave similarly. A smaller proportion of female participants resumes driving later, in the 10th-12th week post-surgery.
Another result of the study was the discrepancy between participants who resided in the countryside and participants who resided in the city with regard to the timing of resumption following surgery. (Figure 3) The authors defined “city” with a population of ≥30.000 and “countryside” with a population of < 30.000. This distinction is arbitrary, however, statistically, it showed significant differences with regard to when patients resumed driving post-surgery. The assumption is that “cities” boast a better transport infrastructure, which can be made use of and thus reduces the need for a car. Participants who reside in the “countryside” resumed driving considerably earlier (the Mode in the “countryside” was 13 participants in the 4th+5th week post-surgery) than participants who reside in the “cities” (the Mode was 19 participants in the 6th+7th week post-surgery). 58.6% of the participants gave a medical reasoning for the first post-operative drive: a journey to a physical therapy appointment or a doctor’s appointment. A hypothesised correlation between size of residential location and reason for the first post-operative drive could not be statistically confirmed (p=0.927).
In a number of studies [4,6,11,12,13,14] the operated side did not influence the postoperative resumption of driving. Our results showcase a different picture: there was no trend in patients who had undergone a THA (p=0.304), in patients who had undergone a TKA, however, there was a trend of patients with a right-side arthroplasty driving significantly later (p=0.020). A possible explanation for this is that driving requires little hip movement, whereas the right knee has the key function of pressing the gas and brake pedals. Thus, roadworthiness largely depends on the functionality and performance of the right knee. Clearly, this aspect is very central to the decision of roadworthiness the patient must make prior to driving.
In a study by Rondon et al. 98.2% of the study participants resumed driving within the first 12 weeks post-surgery. We were able to deliver similar results, 92.4% of our study participants resumed driving in the first 12 weeks post-surgery.
In our study, the average time frame in which participants resumed driving following a TKA or THA was between the 6th and 7th week post-surgery. We were not able to find a significant difference between TKA and THA (p=0.053). By contrast, Rondon et al. discovered a statistically significant difference between knee and hip arthroplasties (TKA = 4.4 weeks, THA = 3.7 weeks).
This discrepancies could be explained by two possible reasons. In Germany, health insurance providers are legally mandated to finance a three-week in-patient postoperative rehabilitation following knee or hip arthroplasty. Our participants were recruited from the patient population in the rehabilitation facility and were therefore all undergoing a three-week in-patient rehabilitation, they were discharged between the 4th and 5th week post-surgery. For our study participants there was therefore no reason to drive before their discharge date. In addition to this, the sample size in this study was considerably smaller (n=92) than the sample size in the study conducted by Rondon et al. (n=1044). This could explain why we were unable to find a statistically significant difference between total knee and hip arthroplasties with regard to the resumption of driving post-surgery. Rondon et al. identified the implementation of postoperative rehabilitation as a reason for later resumption of driving.
We identified a higher risk of being a “late driver” if the participant underwent a right-side procedure or if the participant was female. Rondon et al. delivered similar results, there, too, patients whose right side was operated, and female patients drove later. In addition, we conducted an Odds Ratio test with regard to the risk of resuming driving later post-surgery. An “early driver” was defined as a participant who resumed driving in the 4th+5th week post-surgery. A “late driver” was defined as a participant who resumed driving in the 10th+11th week post-surgery. There was a significantly (p=0.031) 9.00-fold (95% CI 1.01 – 79,54) increased risk for patients who had undergone a right-sided TKA not to resume driving in the 4th+5th week post-surgery. The risk analysis for gender and joint revealed a significant (p=0.00015) 21.08-fold increased risk (95% CI 3.64 – 121.83) of female patients who had undergone TKA resuming driving in the11th+12th week post-surgery. It therefore appears that female participants heed the recommendation given by doctors more than male participants. Consequently, this implies that female patients who have undergone a TKA should receive special guidance and a more intensive rehabilitation program if they intend to drive post-surgery. Of the female participants 13.9% (n=5) did not drive by the 13th week pot-surgery compared to 1.8% (n=1) of the male participants.
Davis et al. (2018) showed that both male and female participants (n=32) achieve their preoperative brake reaction time after the 2nd postoperative week. Most of the participants drove with an automatic transmission. The operated side did not have an impact on how fast the preoperative brake reaction time was achieved. Gender, however, did: male participants reached their preoperative brake reaction earlier than female participants.
In Germany, a driver must evaluate his own roadworthiness before he can start his engine. Roadworthiness is defined as the ability to operate the vehicle safely, regardless of situation. Limitations of roadworthiness, for example drug or alcohol consumption are prosecuted by the legislator, however there are no legislative specifications regarding temporary physical limitations. The driver must evaluate himself in this regard and, provided he decides he is not roadworthy, refrain from driving. This self-evaluation is therefore crucial from a legal standpoint. The present prospective study examines this self-evaluation with regard to roadworthiness.
The Mean age of our male participants as 64.2 years, while the Mean age of our female participants was 60.6 years. The 65-74-year-old participants make up the group of drivers with the lowest accident rate at 21.5 accidents per 1000 drivers per year. If extrapolated to the 3-month span, this would result in 5.4 accidents per 1000 drivers. Rondon et al. reported 0.9% accidents in the 3-month period for knee arthroplasties and 0.4% accidents in the 3-month period for hip arthroplasties. A statistical comparison was not feasible since the accident rate was not elevated in drivers who had undergone TKA or THA when compared to the general age population. Our participants did not report any accidents. From this we can conclude that the self-evaluation of roadworthiness following TKA and THA was adequate and the individual time frame chosen by the participants to resume driving, was responsibly chosen.
After TKA or THA patients experience considerable limitations of the function of their affected leg for an uncertain period of time. This is why they turn to their overseeing doctor or physical therapist, for recommendations regarding post-op resumption of driving. A glance at the current research literature as an anchor or orientation regarding this recommendations, does not deliver consistent evidence.
The available studies can be categorised into two groups: studies which record when patients drive post-surgery and respect their participants’ self-evaluations and studies which use measurable parameters, most often brake reaction time, to recommend when patients can resume driving post-surgery.
In the first group, roadworthiness is already reached two days following a minimally invasive THA (Quarashi et al.), a week following a regular THA (Batra et al.), two weeks following a regular THA (Van der Velden et al.), 3.7 weeks following a regular THA (Rondon et al.) and 6th + 7th weeks post-surgery in the present study. The results for TKA are similarly inconsistent: 4 weeks post-surgery (Van der Velden et al., 4.4 weeks post-surgery (Rondon et al.), 6 weeks post-surgery [Ellanti et al.), and in 6th +7th weeks post-surgery in the present study.
In a review study by Latz et al. a recommendation of 2 to 4 weeks of rest is made before resumption of driving after a TKA or THA. Goodwin et al., on the other hand, recommend 10 days to 8 weeks of rest following a right-sided TKA and 6 to 8 weeks of rest following a right-sided THA before resumption of driving. When it comes to the brake reaction time a similar picture is painted: Marques et al. recorded 44±19 days for the patients to reach their preoperative brake reaction time following a right-sided TKA and 20±15 days following a left-sided TKA. Nizam et al., however, recorded a Median of 3 weeks following a TKA, regardless of side. Van der Velden et al. and Huang et al. saw a return to the preoperative brake reaction time 4 weeks following a TKA and was able to show an inverse correlation between brake reaction time and the “step-test” by Marmon et al..
There were several limitations related to our study. Because most patients with a TKA or THA undergo a three week bedridden rehabilitation in Germany, there is until the end of the 5th postop week, no reason to reuptake driving again. It could be considered that the bedridden rehabilitation impairs the patient to reuptake driving earlier than they actually do. This is a particularity of the German health care system and could be considered a limitation of this study, when compared with other national health care systems, where a bedridden rehabilitation after a TKA or THA is not a common practice. Also the fact that this is a single centre study and although the study sample size was calculated, with the help of a statistician, prior to study begin, it is too small to upscale this study results at the national level and only reflects the postoperative driving practices after TKA or THA of one region of Germany.
The large bandwidth of results across the board and the resulting variance of recommendations likely leave the patient at a loss. An operational approach which would examine the skills required for safe driving and base recommendations on these parameters would be more practical. A low pain level, sufficient range of motion (ROM) of the affected joint, unaided walking, safe entrance and exit from the vehicle, a preferably high score in the “step-test” and an acceptable brake reaction time seem to be the most crucial parameters to develop individual recommendations for patients. What role these parameters play in the decision-making process for the postoperative resumption of driving following a TKA or THA is unclear. Furthermore the patient self-evaluation after a TKA or THA procedure is, at least in Germany, the main criterion for making the decision when to resume driving again. Further research is required to examine the significance of these parameters in recommendations.